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=={{header|Racket}}==
=={{header|Racket}}==

<lang racket>#lang racket

(require racket/set)

(define (abbr-length ss)
(for*/first ((l (in-range 1 (string-length (argmax string-length ss))))
#:when (equal? (sequence-length
(for/set ((s ss))
(substring s 0 (min l (string-length s)))))
(length ss)))
l))

(module+ main
(define report-line
(match-lambda
["" ""]
[(and s (app string-split ss)) (format "~a ~a" (abbr-length ss) s)]))
(for-each (compose displayln report-line) (take (file->lines "data.txt") 5)))</lang>

{{out}}
<pre>2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit</pre>


=={{header|Raku}}==
=={{header|Raku}}==

Revision as of 18:22, 28 August 2021

Task
Abbreviations, automatic
You are encouraged to solve this task according to the task description, using any language you may know.

The use of   abbreviations   (also sometimes called synonyms, nicknames, AKAs, or aliases)   can be an
easy way to add flexibility when specifying or using commands, sub─commands, options, etc.


It would make a list of words easier to maintain   (as words are added, changed, and/or deleted)   if the minimum abbreviation length of that list could be automatically (programmatically) determined.


For this task, use the list (below) of the days-of-the-week names that are expressed in about a hundred languages   (note that there is a blank line in the list).

Sunday Monday Tuesday Wednesday Thursday Friday Saturday
Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
Ehud Segno Maksegno Erob Hamus Arbe Kedame
Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
domingu llunes martes miércoles xueves vienres sábadu
Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
nedelia ponedelnik vtornik sriada chetvartak petak sabota
sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
dimanche lundi mardi mercredi jeudi vendredi samedi
Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
Domingo Segunda_feira Martes Mércores Joves Venres Sábado
k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
vasárnap hétfö kedd szerda csütörtök péntek szombat
Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
sundio lundio mardio merkurdio jovdio venerdio saturdio
Minggu Senin Selasa Rabu Kamis Jumat Sabtu
Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
domenica lunedí martedí mercoledí giovedí venerdí sabato
Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
Jabot Manre Juje Wonje Taije Balaire Jarere
geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
sφndag mandag tirsdag onsdag torsdag fredag lφrdag
lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
djadomingo djaluna djamars djarason djaweps djabièrna djasabra
Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
Domingo Lunes martes Miercoles Jueves Viernes Sabado
Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
nedel^a pondelok utorok streda s^tvrtok piatok sobota
Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
domingo lunes martes miércoles jueves viernes sábado
sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
söndag måndag tisdag onsdag torsdag fredag lordag
Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
zuntik montik dinstik mitvokh donershtik fraytik shabes
iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
Sun Moon Mars Mercury Jove Venus Saturn
zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Caveat:   The list (above) most surely contains errors (or, at the least, differences) of what the actual (or true) names for the days-of-the-week.


To make this Rosetta Code task page as small as possible, if processing the complete list, read the days-of-the-week from a file (that is created from the above list).


Notes concerning the above list of words

  •   each line has a list of days-of-the-week for a language, separated by at least one blank
  •   the words on each line happen to be in order, from Sunday ──► Saturday
  •   most lines have words in mixed case and some have all manner of accented words and other characters
  •   some words were translated to the nearest character that was available to code page   437
  •   the characters in the words are not restricted except that they may not have imbedded blanks
  •   for this example, the use of an underscore (_) was used to indicate a blank in a word


Task
  •   The list of words   (days of the week)   needn't be verified/validated.
  •   Write a function to find the (numeric) minimum length abbreviation for each line that would make abbreviations unique.
  •   A blank line   (or a null line)   should return a null string.
  •   Process and show the output for at least the first five lines of the file.
  •   Show all output here.
Other tasks related to string operations:
Metrics
Counting
Remove/replace
Anagrams/Derangements/shuffling
Find/Search/Determine
Formatting
Song lyrics/poems/Mad Libs/phrases
Tokenize
Sequences



11l

Translation of: Python

<lang 11l>F shortest_abbreviation_length(line, list_size)

  V words = line.split(‘ ’)
  V word_count = words.len
  I word_count != list_size
     X ValueError(‘Not enough entries, expected #. found #.’.format(list_size, word_count))
  V abbreviation_length = 1
  L
     V abbreviations = Set(words.map(word -> word[0 .< @abbreviation_length]))
     I abbreviations.len == list_size
        R abbreviation_length
     abbreviation_length++

F automatic_abbreviations(filename, words_per_line)

  L(line) File(filename).read().split("\n")
     I line.len > 0
        V length = shortest_abbreviation_length(line, words_per_line)
        print(‘#2 #.’.format(length, line))
     E
        print()

automatic_abbreviations(‘daysOfWeek.txt’, 7)</lang>

Output:
 2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
 2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2 domingu llunes martes miércoles xueves vienres sábadu
 2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
 6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
 2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
 2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
 1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

 7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
 2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2 dimanche lundi mardi mercredi jeudi vendredi samedi
 4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
 2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
 7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3 vasárnap hétfö kedd szerda csütörtök péntek szombat
 2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
 2 sundio lundio mardio merkurdio jovdio venerdio saturdio
 3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
 2 domenica lunedí martedí mercoledí giovedí venerdí sabato
 2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3 Jabot Manre Juje Wonje Taije Balaire Jarere
 5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
 2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
 7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
 4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
 2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
 1 Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
 2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2 domingo lunes martes miércoles jueves viernes sábado
 2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2 söndag måndag tisdag onsdag torsdag fredag lordag
 2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
 7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
 2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
 6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2 zuntik montik dinstik mitvokh donershtik fraytik shabes
 7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
 2 Sun Moon Mars Mercury Jove Venus Saturn
 2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
 7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
 2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

AArch64 Assembly

Works with: as version Raspberry Pi 3B version Buster 64 bits

<lang AArch64 Assembly> /* ARM assembly AARCH64 Raspberry PI 3B */ /* program abbrAuto64.s */ /* store list of day in a file listDays.txt*/ /* and run the program abbrAuto64 listDays.txt */

/*******************************************/ /* Constantes file */ /*******************************************/ /* for this file see task include a file in language AArch64 assembly*/ .include "../includeConstantesARM64.inc"

.equ BUFFERSIZE, 10000 .equ NBMAXIDAYS, 7

/*********************************/ /* Initialized data */ /*********************************/ .data szMessTitre: .asciz "Nom du fichier : " szCarriageReturn: .asciz "\n" szMessErreur: .asciz "Error detected.\n" szMessErrBuffer: .asciz "buffer size too less !!" szSpace: .asciz " " /*********************************/ /* UnInitialized data */ /*********************************/ .bss .align 4 sZoneConv: .skip 24 qAdrFicName: .skip 8 iTabAdrDays: .skip 8 * NBMAXIDAYS iTabAdrDays2: .skip 8 * NBMAXIDAYS sBufferDays: .skip BUFFERSIZE sBuffer: .skip BUFFERSIZE /*********************************/ /* code section */ /*********************************/ .text .global main main: // INFO: main

   mov x0,sp                        // stack address for load parameter
   bl traitFic                      // read file and process 

100: // standard end of the program

   mov x0, #0                       // return code
   mov x8, #EXIT                    // request to exit program
   svc #0                           // perform the system call

qAdrszCarriageReturn: .quad szCarriageReturn qAdrsZoneConv: .quad sZoneConv

/******************************************************************/ /* read file */ /******************************************************************/ /* x0 contains address stack begin */ traitFic: // INFO: traitFic

   stp x1,lr,[sp,-16]!               // save  registres
   stp x2,x3,[sp,-16]!               // save  registres
   stp x4,x5,[sp,-16]!               // save  registres
   stp x6,x7,[sp,-16]!               // save  registres
   stp x8,fp,[sp,-16]!               // save  registres
   mov fp,x0                         //  fp <- start address
   ldr x4,[fp]                       // number of Command line arguments
   cmp x4,#1
   ble 99f
   add x5,fp,#16                      // second parameter address 
   ldr x5,[x5]
   ldr x0,qAdrqAdrFicName
   str x5,[x0]
   ldr x0,qAdrszMessTitre
   bl affichageMess                  // display string
   mov x0,x5
   bl affichageMess 
   ldr x0,qAdrszCarriageReturn
   bl affichageMess                  // display carriage return
   
   mov x0,AT_FDCWD
   mov x1,x5                         // file name
   mov x2,#O_RDWR                    // flags    
   mov x3,#0                         // mode 
   mov x8, #OPEN                     // call system OPEN 
   svc 0 
   cmp x0,#0                         // error ?
   ble 99f
   mov x7,x0                         // File Descriptor
   ldr x1,qAdrsBufferDays             // buffer address
   mov x2,#BUFFERSIZE                // buffer size
   mov x8,#READ                      // read file
   svc #0
   cmp x0,#0                         // error ?
   blt 99f
   // extraction datas
   ldr x1,qAdrsBufferDays             // buffer address
   add x1,x1,x0
   mov x0,#0                         // store zéro final
   strb w0,[x1] 
   ldr x0,qAdriTabAdrDays             // key string command table
   ldr x1,qAdrsBufferDays             // buffer address
   bl extracDatas
                                      // close file
   mov x0,x7
   mov x8, #CLOSE 
   svc 0 
   mov x0,#0
   b 100f

99: // error

   ldr x0,qAdrszMessErreur            // error message
   bl  affichageMess
   mov x0,#-1

100:

   ldp x8,fp,[sp],16                  // restaur des  2 registres
   ldp x6,x7,[sp],16                  // restaur des  2 registres
   ldp x4,x5,[sp],16                  // restaur des  2 registres
   ldp x2,x3,[sp],16                  // restaur des  2 registres
   ldp x1,lr,[sp],16                  // restaur des  2 registres
   ret

qAdrqAdrFicName: .quad qAdrFicName qAdrszMessTitre: .quad szMessTitre qAdrszMessErreur: .quad szMessErreur qAdrsBuffer: .quad sBuffer qAdrsBufferDays: .quad sBufferDays qAdriTabAdrDays: .quad iTabAdrDays /******************************************************************/ /* extrac lines file buffer */ /******************************************************************/ /* x0 contains strings address */ /* x1 contains buffer address */ extracDatas: // INFO: extracDatas

   stp x1,lr,[sp,-16]!          // save  registres
   stp x2,x3,[sp,-16]!          // save  registres
   stp x4,x5,[sp,-16]!          // save  registres
   stp x6,x7,[sp,-16]!          // save  registres
   stp x8,fp,[sp,-16]!          // save  registres
   mov x7,x0
   mov x6,x1
   mov x2,#0                    // string buffer indice
   mov x4,x1                    // start string
   mov x5,#0                    // string index

1:

   ldrb w3,[x6,x2]
   cmp w3,#0
   beq 4f                       // end
   cmp w3,#0xA
   beq 2f
   cmp w3,#' '                  // end string
   beq 3f
   add x2,x2,#1
   b 1b

2:

   mov x3,#0
   strb w3,[x6,x2]
   ldrb w3,[x6,x2]
   cmp w3,#0xD
   bne 21f
   add x2,x2,#2
   b 22f

21:

   add x2,x2,#1

22:

   mov x0,x4                   // store last day of line in table
   str x4,[x7,x5,lsl #3]
   mov x0,x5                   // days number
   bl traitLine                // process a line of days
   mov x5,#0                   // new line
   b 5f

3:

   mov x3,#0
   strb w3,[x6,x2]
   add x2,x2,#1

4:

   mov x0,x4
   str x4,[x7,x5,lsl #3]
   add x5,x5,#1

5: // supress spaces

   ldrb w3,[x6,x2]
   cmp w3,#0
   beq 100f
   cmp w3,#' '
   cinc x2,x2,eq
   beq 5b
   
   add x4,x6,x2                 // new start address
   b 1b

100:

   ldp x8,fp,[sp],16           // restaur des  2 registres
   ldp x6,x7,[sp],16           // restaur des  2 registres
   ldp x4,x5,[sp],16           // restaur des  2 registres
   ldp x2,x3,[sp],16           // restaur des  2 registres
   ldp x1,lr,[sp],16           // restaur des  2 registres
   ret

/******************************************************************/ /* processing a line */ /******************************************************************/ /* x0 contains days number in table */ traitLine: // INFO: traitLine

   stp x1,lr,[sp,-16]!          // save  registres
   stp x2,x3,[sp,-16]!          // save  registres
   stp x4,x5,[sp,-16]!          // save  registres
   stp x6,x7,[sp,-16]!          // save  registres
   stp x8,x9,[sp,-16]!          // save  registres
   stp x10,x11,[sp,-16]!          // save  registres
   stp x12,x13,[sp,-16]!          // save  registres
   cmp x0,#1                 // one day ?
   bgt 1f                    // no
   ldr x0,qAdrszCarriageReturn // yes display empty line
   bl affichageMess
   b 100f

1: // line OK

   mov x6,x0                 // days number
   ldr x0,qAdriTabAdrDays
   ldr x1,qAdriTabAdrDays2
   mov x2,#0

11: // copy days table into other for display final

   ldr x3,[x0,x2,lsl #3]
   str x3,[x1,x2,lsl #3]
   add x2,x2,#1
   cmp x2,x6
   ble 11b
   ldr x0,qAdriTabAdrDays    // and sort first table
   mov x1,#0
   add x2,x6,#1
   bl insertionSort
   
   mov x8,#1                 // abbrevations counter
   ldr x12,qAdriTabAdrDays
   mov x2,#0
   ldr x10,[x12,x2,lsl #3]   // load first sorting day
   mov x11,#0
   mov x3,#1

2: // begin loop

   ldr x4,[x12,x3,lsl #3]    // load other day
   mov x0,x10                // day1
   mov x1,x4                 // day 2
   mov x2,#0                 // position 0
   bl compareChar
   cmp x0,#0                 // first letter equal ?
   beq 3f
   mov x10,x4                // no -> move day 2 in day 1
   b 6f

3: // if equal

   mov x7,x1                 // characters length (1,2,3)
   mov x11,#1                // letters position

4: // loop to compare letters days

   mov x0,x10
   mov x1,x4
   mov x2,x7
   bl compareChar
   cmp x0,#0
   bne 5f
   cmp x5,#0                 // if end
   beq 5f
   add x7,x7,x1              // next character
   add x11,x11,#1            // count letter
   b 4b

5:

   add x11,x11,#1            // increment letters position
   cmp x11,x8                // and store if > position précedente
   csel x8,x11,x8,gt
   //movgt x8,x11
   mov x10,x4                 // and day1 = day2
   

6:

   add x3,x3,#1              // increment day
   cmp x3,x6                 
   ble 2b                    // and loop
   
   mov x0,x8                 // display position letter
   ldr x1,qAdrsZoneConv
   bl conversion10
   //mov x2,#0
   //strb x2,[x1,x0]
   ldr x0,qAdrsZoneConv
   bl affichageMess
   ldr x0,qAdrszSpace
   bl affichageMess
   ldr x0,qAdriTabAdrDays2   // and display list origine days
   mov x1,x6
   bl displayListDays
   

100:

   ldp x12,x13,[sp],16         // restaur des  2 registres
   ldp x10,x11,[sp],16         // restaur des  2 registres
   ldp x8,x9,[sp],16           // restaur des  2 registres
   ldp x6,x7,[sp],16           // restaur des  2 registres
   ldp x4,x5,[sp],16           // restaur des  2 registres
   ldp x2,x3,[sp],16           // restaur des  2 registres
   ldp x1,lr,[sp],16           // restaur des  2 registres
   ret

qAdrszSpace: .quad szSpace qAdriTabAdrDays2: .quad iTabAdrDays2 /******************************************************************/ /* comparison character unicode */ /******************************************************************/ /* x0 contains address first string */ /* x1 contains address second string */ /* x2 contains the character position to compare */ /* x0 return 0 if equal 1 if > -1 if < */ /* x1 return character S1 size in octet if equal */ /* x2 return character S2 size in octet */ compareChar:

   stp lr,x3,[sp,-16]!          // save  registres
   stp x4,x5,[sp,-16]!          // save  registres
   stp x6,x7,[sp,-16]!          // save  registres
   stp x8,x9,[sp,-16]!          // save  registres
   ldrb w3,[x0,x2]
   ldrb w4,[x1,x2]
   cmp w3,w4                    // compare first byte
   blt 3f
   bgt 4f
   bne 100f
   and w3,w3,#0b11100000           // 3 bytes ?
   cmp w3,#0b11100000
   bne 1f
   add x2,x2,#1
   ldrb w3,[x0,x2]
   ldrb w4,[x1,x2]
   cmp w3,w4
   blt 3f
   bgt 4f
   bne 100f
   add x2,x2,#1
   ldrb w3,[x0,x2]
   ldrb w4,[x1,x2]
   cmp w3,w4
   blt 3f
   bgt 4f
   bne 100f
   mov x0,#0
   mov x1,#3
   b 100f

1:

   cmp w3,#0b11000000           // 2 bytes ?
   bne 2f
   add x2,x2,#1
   ldrb w3,[x0,x2]
   ldrb w4,[x1,x2]
   cmp w3,w4
   blt 3f
   bgt 4f
   bne 100f
   mov x0,#0
   mov x1,#2
   b 100f

2: // 1 byte

   mov x0,#0
   mov x1,#1
   b 100f

3:

   mov x0,#-1
   b 100f

4:

   mov x0,#1

100:

   ldp x8,x9,[sp],16           // restaur des  2 registres
   ldp x6,x7,[sp],16           // restaur des  2 registres
   ldp x4,x5,[sp],16           // restaur des  2 registres
   ldp lr,x3,[sp],16           // restaur des  2 registres
   ret

/******************************************************************/ /* control load */ /******************************************************************/ /* x0 contains string table */ /* x1 contains days number */ displayListDays:

   stp x1,lr,[sp,-16]!          // save  registres
   stp x2,x3,[sp,-16]!          // save  registres
   stp x4,x5,[sp,-16]!          // save  registres
   stp x6,x7,[sp,-16]!          // save  registres
   stp x8,x9,[sp,-16]!          // save  registres
   mov x5,x0
   mov x2,#0

1:

   cmp x2,x1
   bgt 2f
   ldr x0,[x5,x2,lsl #3]
   bl affichageMess
   ldr x0,qAdrszSpace
   bl affichageMess
   add x2,x2,#1
   b 1b

2:

   ldr x0,qAdrszCarriageReturn
   bl affichageMess

100:

   ldp x8,x9,[sp],16           // restaur des  2 registres
   ldp x6,x7,[sp],16           // restaur des  2 registres
   ldp x4,x5,[sp],16           // restaur des  2 registres
   ldp x2,x3,[sp],16           // restaur des  2 registres
   ldp x1,lr,[sp],16           // restaur des  2 registres
   ret

/************************************/ /* Strings case sensitive comparisons */ /************************************/ /* x0 et x1 contains the address of strings */ /* return 0 in x0 if equals */ /* return -1 if string x0 < string x1 */ /* return 1 if string x0 > string x1 */ comparStrings:

   stp x1,lr,[sp,-16]!          // save  registres
   stp x2,x3,[sp,-16]!          // save  registres
   stp x4,x5,[sp,-16]!          // save  registres
   mov x2,#0                // counter

1:

   ldrb w3,[x0,x2]          // byte string 1
   ldrb w4,[x1,x2]          // byte string 2
   cmp w3,w4
   blt 2f
   bgt 3f
   bne 100f                 // not equals
   cmp w3,#0                // 0 end string
   beq 4f                   // end string
   add x2,x2,#1             // else add 1 in counter
   b 1b                     // and loop

2:

   mov x0,#-1               // small
   b 100f

3:

   mov x0,#1                // greather
   b 100f

4:

   mov x0,#0                // equal 

100:

   ldp x4,x5,[sp],16           // restaur des  2 registres
   ldp x2,x3,[sp],16           // restaur des  2 registres
   ldp x1,lr,[sp],16           // restaur des  2 registres
   ret

/******************************************************************/ /* insertion sort */ /******************************************************************/ /* x0 contains the address of table */ /* x1 contains the first element */ /* x2 contains the number of element */ insertionSort:

   stp x1,lr,[sp,-16]!          // save  registres
   stp x2,x3,[sp,-16]!          // save  registres
   stp x4,x5,[sp,-16]!          // save  registres
   stp x6,x7,[sp,-16]!          // save  registres
   mov x6,x0
   add x3,x1,#1                       // start index i

1: // start loop

   ldr x1,[x6,x3,lsl #3]              // load value A[i]
   sub x5,x3,#1                       // index j

2:

   ldr x4,[x6,x5,lsl #3]              // load value A[j]
   mov x0,x4
   bl comparStrings
   cmp x0,#1                          // compare value
   bne 3f
   add x5,x5,#1                          // increment index j
   str x4,[x6,x5,lsl #3]              // store value A[j+1]
   subs x5,x5,#2                         // j = j - 1
   bge 2b                             // loop if j >= 0

3:

   add x5,x5,#1                          // increment index j
   str x1,[x6,x5,lsl #3]              // store value A[i] in A[j+1]
   add x3,x3,#1                          // increment index i
   cmp x3,x2                          // end ?
   blt 1b                             // no -> loop

100:

   ldp x6,x7,[sp],16           // restaur des  2 registres
   ldp x4,x5,[sp],16           // restaur des  2 registres
   ldp x2,x3,[sp],16           // restaur des  2 registres
   ldp x1,lr,[sp],16           // restaur des  2 registres
   ret

/********************************************************/ /* File Include fonctions */ /********************************************************/ /* for this file see task include a file in language AArch64 assembly */ .include "../includeARM64.inc"

</lang>

Nom du fichier : listDays.txt
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2 domingu llunes martes miércoles xueves vienres sábadu
2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
2 dimanche lundi mardi mercredi jeudi vendredi samedi
4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
3 vasárnap hétfö kedd szerda csütörtök péntek szombat
2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
2 sundio lundio mardio merkurdio jovdio venerdio saturdio
3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
2 domenica lunedí martedí mercoledí giovedí venerdí sabato
2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
3 Jabot Manre Juje Wonje Taije Balaire Jarere
5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
1 Domingo Lunes martes Miercoles Jueves Viernes Sabado
2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
2 domingo lunes martes miércoles jueves viernes sábado
2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
2 söndag måndag tisdag onsdag torsdag fredag lordag
2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
2 zuntik montik dinstik mitvokh donershtik fraytik shabes
7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
2 Sun Moon Mars Mercury Jove Venus Saturn
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

ARM Assembly

Works with: as version Raspberry Pi

<lang ARM Assembly> /* ARM assembly Raspberry PI */ /* program abbrAuto.s */ /* store list of day in a file listDays.txt*/ /* and run the program abbrAuto listDays.txt */

/* REMARK 1 : this program use routines in a include file

  see task Include a file language arm assembly 
  for the routine affichageMess conversion10 
  see at end of this program the instruction include */

/* for constantes see task include a file in arm assembly */ /************************************/ /* Constantes */ /************************************/ .include "../constantes.inc"

.equ STDIN, 0 @ Linux input console .equ STDOUT, 1 @ Linux output console .equ EXIT, 1 @ Linux syscall .equ READ, 3 @ Linux syscall .equ WRITE, 4 @ Linux syscall .equ OPEN, 5 @ Linux syscall .equ CLOSE, 6 @ Linux syscall

.equ O_RDWR, 0x0002 @ open for reading and writing

.equ BUFFERSIZE, 10000 .equ NBMAXIDAYS, 7

/*********************************/ /* Initialized data */ /*********************************/ .data szMessTitre: .asciz "Nom du fichier : " szCarriageReturn: .asciz "\n" szMessErreur: .asciz "Error detected.\n" szMessErrBuffer: .asciz "buffer size too less !!" szSpace: .asciz " " /*********************************/ /* UnInitialized data */ /*********************************/ .bss .align 4 sZoneConv: .skip 24 iAdrFicName: .skip 4 iTabAdrDays: .skip 4 * NBMAXIDAYS iTabAdrDays2: .skip 4 * NBMAXIDAYS sBufferDays: .skip BUFFERSIZE sBuffer: .skip BUFFERSIZE /*********************************/ /* code section */ /*********************************/ .text .global main main: @ INFO: main

   mov r0,sp                        @ stack address for load parameter
   bl traitFic                      @ read file and process 

100: @ standard end of the program

   mov r0, #0                       @ return code
   mov r7, #EXIT                    @ request to exit program
   svc #0                           @ perform the system call

iAdrszCarriageReturn: .int szCarriageReturn //iAdrszMessErrBuffer: .int szMessErrBuffer iAdrsZoneConv: .int sZoneConv


/******************************************************************/ /* read file */ /******************************************************************/ /* r0 contains address stack begin */ traitFic: @ INFO: traitFic

   push {r1-r8,fp,lr}                @ save  registers
   mov fp,r0                         @  fp <- start address
   ldr r4,[fp]                       @ number of Command line arguments
   cmp r4,#1
   movle r0,#-1
   ble 99f
   add r5,fp,#8                      @ second parameter address 
   ldr r5,[r5]
   ldr r0,iAdriAdrFicName
   str r5,[r0]
   ldr r0,iAdrszMessTitre
   bl affichageMess                  @ display string
   mov r0,r5
   bl affichageMess 
   ldr r0,iAdrszCarriageReturn
   bl affichageMess                  @ display carriage return
   mov r0,r5                         @ file name
   mov r1,#O_RDWR                    @ flags    
   mov r2,#0                         @ mode 
   mov r7, #OPEN                     @ call system OPEN 
   svc 0 
   cmp r0,#0                         @ error ?
   ble 99f
   mov r8,r0                         @ File Descriptor
   ldr r1,iAdrsBufferDays             @ buffer address
   mov r2,#BUFFERSIZE                @ buffer size
   mov r7,#READ                      @ read file
   svc #0
   cmp r0,#0                         @ error ?
   blt 99f
   @ extraction datas
   ldr r1,iAdrsBufferDays             @ buffer address
   add r1,r0
   mov r0,#0                         @ store zéro final
   strb r0,[r1] 
   ldr r0,iAdriTabAdrDays             @ key string command table
   ldr r1,iAdrsBufferDays             @ buffer address
   bl extracDatas
                                     @ close file
   mov r0,r8
   mov r7, #CLOSE 
   svc 0 
   mov r0,#0
   b 100f

99: @ error

   ldr r1,iAdrszMessErreur           @ error message
   bl   displayError
   mov r0,#-1

100:

   pop {r1-r8,fp,lr}                 @ restaur registers 
   bx lr                             @return

iAdriAdrFicName: .int iAdrFicName iAdrszMessTitre: .int szMessTitre iAdrszMessErreur: .int szMessErreur iAdrsBuffer: .int sBuffer iAdrsBufferDays: .int sBufferDays iAdriTabAdrDays: .int iTabAdrDays /******************************************************************/ /* extrac lines file buffer */ /******************************************************************/ /* r0 contains strings address */ /* r1 contains buffer address */ extracDatas: @ INFO: extracDatas

   push {r1-r8,lr}              @ save  registers
   mov r7,r0
   mov r6,r1
   mov r2,#0                    @ string buffer indice
   mov r4,r1                    @ start string
   mov r5,#0                    @ string index

1:

   ldrb r3,[r6,r2]
   cmp r3,#0
   beq 4f                       @ end
   cmp r3,#0xA
   beq 2f
   cmp r3,#' '                  @ end string
   beq 3f
   add r2,#1
   b 1b

2:

   mov r3,#0
   strb r3,[r6,r2]
   ldrb r3,[r6,r2]
   cmp r3,#0xD
   addeq r2,#2
   addne r2,#1
   mov r0,r4                   @ store last day of line in table
   str r4,[r7,r5,lsl #2]
   mov r0,r5                   @ days number
   bl traitLine                @ process a line of days
   mov r5,#0                   @ new line
   b 5f

3:

   mov r3,#0
   strb r3,[r6,r2]
   add r2,#1

4:

   mov r0,r4
   str r4,[r7,r5,lsl #2]
   add r5,#1

5: @ supress spaces

   ldrb r3,[r6,r2]
   cmp r3,#0
   beq 100f
   cmp r3,#' '
   addeq r2,r2,#1
   beq 5b
   
   add r4,r6,r2                 @ new start address
   b 1b

100:

   pop {r1-r8,lr}               @ restaur registers 
   bx lr                        @return
   

/******************************************************************/ /* processing a line */ /******************************************************************/ /* r0 contains days number in table */ traitLine: @ INFO: traitLine

   push {r1-r12,lr}           @ save  register
   cmp r0,#1                 @ one day ?
   bgt 1f                    @ no
   ldr r0,iAdrszCarriageReturn @ yes display empty line
   bl affichageMess
   b 100f

1: @ line OK

   mov r6,r0                 @ days number
   ldr r0,iAdriTabAdrDays
   ldr r1,iAdriTabAdrDays2
   mov r2,#0

11: @ copy days table into other for display final

   ldr r3,[r0,r2,lsl #2]
   str r3,[r1,r2,lsl #2]
   add r2,#1
   cmp r2,r6
   ble 11b
   ldr r0,iAdriTabAdrDays    @ and sort first table
   mov r1,#0
   add r2,r6,#1
   bl insertionSort
   
   mov r8,#1                 @ abbrevations counter
   ldr r12,iAdriTabAdrDays
   mov r2,#0
   ldr r10,[r12,r2,lsl #2]   @ load first sorting day
   mov r11,#0
   mov r3,#1

2: @ begin loop

   ldr r4,[r12,r3,lsl #2]    @ load other day
   @ 1er lettre identique
   mov r0,r10                @ day1
   mov r1,r4                 @ day 2
   mov r2,#0                 @ position 0
   bl compareChar
   cmp r0,#0                 @ first letter equal ?
   movne r10,r4              @ no -> move day 2 in day 1
   bne 6f

3: @ if equal

   mov r7,r1                 @ characters length (1,2,3)
   mov r11,#1                @ letters position

4: @ loop to compare letters days

   mov r0,r10
   mov r1,r4
   mov r2,r7
   bl compareChar
   cmp r0,#0
   bne 5f
   cmp r5,#0                 @ if end
   beq 5f
   add r7,r7,r1              @ next character
   add r11,r11,#1            @ count letter
   b 4b

5:

   add r11,r11,#1            @ increment letters position
   cmp r11,r8                @ and store if > position précedente
   movgt r8,r11
   mov r10,r4                 @ and day1 = day2
   

6:

   add r3,r3,#1              @ increment day
   cmp r3,r6                 
   ble 2b                    @ and loop
   
   mov r0,r8                 @ display position letter
   ldr r1,iAdrsZoneConv
   bl conversion10
   mov r2,#0
   strb r2,[r1,r0]
   ldr r0,iAdrsZoneConv
   bl affichageMess
   ldr r0,iAdrszSpace
   bl affichageMess
   ldr r0,iAdriTabAdrDays2   @ and display list origine days
   mov r1,r6
   bl displayListDays
   

100:

   pop {r1-r12,lr}              @ restaur registers 
   bx lr                        @return 

iAdrszSpace: .int szSpace iAdriTabAdrDays2: .int iTabAdrDays2 /******************************************************************/ /* comparison character unicode */ /******************************************************************/ /* r0 contains address first string */ /* r1 contains address second string */ /* r2 contains the character position to compare */ /* r0 return 0 if equal 1 if > -1 if < */ /* r1 return character S1 size in octet if equal */ /* r2 return character S2 size in octet */ compareChar:

   push {r3-r8,lr}              @ save  registers
   ldrb r3,[r0,r2]
   ldrb r4,[r1,r2]
   cmp r3,r4                    @ compare first byte
   movlt r0,#-1
   movgt r0,#1 
   bne 100f
   and r3,#0b11100000           @ 3 bytes ?
   cmp r3,#0b11100000
   bne 1f
   add r2,#1
   ldrb r3,[r0,r2]
   ldrb r4,[r1,r2]
   cmp r3,r4
   movlt r0,#-1
   movgt r0,#1 
   bne 100f
   add r2,#1
   ldrb r3,[r0,r2]
   ldrb r4,[r1,r2]
   cmp r3,r4
   movlt r0,#-1
   movgt r0,#1 
   bne 100f
   mov r0,#0
   mov r1,#3
   b 100f

1:

   and r3,#0b11100000           @ 2 bytes ?
   cmp r3,#0b11000000
   bne 2f
   add r2,#1
   ldrb r3,[r0,r2]
   ldrb r4,[r1,r2]
   cmp r3,r4
   movlt r0,#-1
   movgt r0,#1 
   bne 100f
   mov r0,#0
   mov r1,#2
   b 100f

2: @ 1 byte

   mov r0,#0
   mov r1,#1

100:

   pop {r3-r8,lr}              @ restaur registers 
   bx lr                       @return

/******************************************************************/ /* control load */ /******************************************************************/ /* r0 contains string table */ /* r1 contains days number */ displayListDays:

   push {r1-r8,lr}              @ save  registers
   mov r5,r0
   mov r2,#0

1:

   cmp r2,r1
   bgt 2f
   ldr r0,[r5,r2,lsl #2]
   bl affichageMess
   ldr r0,iAdrszSpace
   bl affichageMess
   add r2,r2,#1
   b 1b

2:

   ldr r0,iAdrszCarriageReturn
   bl affichageMess

100:

   pop {r1-r8,lr}               @ restaur registers 
   bx lr                        @return

/************************************/ /* Strings case sensitive comparisons */ /************************************/ /* r0 et r1 contains the address of strings */ /* return 0 in r0 if equals */ /* return -1 if string r0 < string r1 */ /* return 1 if string r0 > string r1 */ comparStrings:

   push {r1-r4}             @ save des registres
   mov r2,#0                @ counter

1:

   ldrb r3,[r0,r2]          @ byte string 1
   ldrb r4,[r1,r2]          @ byte string 2
   cmp r3,r4
   movlt r0,#-1             @ small
   movgt r0,#1              @ greather
   bne 100f                 @ not equals
   cmp r3,#0                @ 0 end string
   moveq r0,#0              @ equal 
   beq 100f                 @ end string
   add r2,r2,#1             @ else add 1 in counter
   b 1b                     @ and loop

100:

   pop {r1-r4}
   bx lr   

/******************************************************************/ /* insertion sort */ /******************************************************************/ /* r0 contains the address of table */ /* r1 contains the first element */ /* r2 contains the number of element */ insertionSort:

   push {r1-r6,lr}                    @ save registers
   mov r6,r0
   add r3,r1,#1                       @ start index i

1: @ start loop

   ldr r1,[r6,r3,lsl #2]              @ load value A[i]
   sub r5,r3,#1                       @ index j

2:

   ldr r4,[r6,r5,lsl #2]              @ load value A[j]
   mov r0,r4
   bl comparStrings
   cmp r0,#1                          @ compare value
   bne 3f
   add r5,#1                          @ increment index j
   str r4,[r6,r5,lsl #2]              @ store value A[j+1]
   subs r5,#2                         @ j = j - 1
   bge 2b                             @ loop if j >= 0

3:

   add r5,#1                          @ increment index j
   str r1,[r6,r5,lsl #2]              @ store value A[i] in A[j+1]
   add r3,#1                          @ increment index i
   cmp r3,r2                          @ end ?
   blt 1b                             @ no -> loop

100:

   pop {r1-r6,lr}
   bx lr   

/***************************************************/ /* ROUTINES INCLUDE */ /***************************************************/ .include "../affichage.inc" </lang>

Nom du fichier : listDays.txt
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2 domingu llunes martes miércoles xueves vienres sábadu
2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
2 dimanche lundi mardi mercredi jeudi vendredi samedi
4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
3 vasárnap hétfö kedd szerda csütörtök péntek szombat
2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
2 sundio lundio mardio merkurdio jovdio venerdio saturdio
3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
2 domenica lunedí martedí mercoledí giovedí venerdí sabato
2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
3 Jabot Manre Juje Wonje Taije Balaire Jarere
5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
1 Domingo Lunes martes Miercoles Jueves Viernes Sabado
2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
2 domingo lunes martes miércoles jueves viernes sábado
2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
2 söndag måndag tisdag onsdag torsdag fredag lordag
2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
2 zuntik montik dinstik mitvokh donershtik fraytik shabes
7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
2 Sun Moon Mars Mercury Jove Venus Saturn
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

AWK

<lang AWK>

  1. syntax: GAWK -f ABBREVIATIONS_AUTOMATIC.AWK ABBREVIATIONS_AUTOMATIC.TXT

{ dow_arr[NR] = $0 } END {

   for (i=1; i<=NR; i++) {
     if (split(dow_arr[i],arr1,FS) != 7) {
       printf("NG %s\n",dow_arr[i])
       continue
     }
     col_width = 0
     for (j=1; j<=7; j++) {
       col_width = max(col_width,length(arr1[j]))
     }
     for (col=1; col<=col_width; col++) {
       delete arr2
       for (j=1; j<=7; j++) {
         arr2[toupper(substr(arr1[j],1,col))]
       }
       if (length(arr2) == 7) {
         break
       }
       if (col >= col_width) { # catches duplicate day names
         col = "NG"
         break
       }
     }
     printf("%2s %s\n",col,dow_arr[i])
   }
   exit(0)

} function max(x,y) { return((x > y) ? x : y) } </lang>

Output:
 2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
 2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2 domingu llunes martes miércoles xueves vienres sábadu
 2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
 6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
 2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
 2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
 1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
NG
 7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
 2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2 dimanche lundi mardi mercredi jeudi vendredi samedi
 4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
 2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
 7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3 vasárnap hétfö kedd szerda csütörtök péntek szombat
 2 Sunnudagur Mánudagur ¦ridjudagur Midvikudagar Fimmtudagur FÖstudagur Laugardagur
 2 sundio lundio mardio merkurdio jovdio venerdio saturdio
 3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
 2 domenica lunedí martedí mercoledí giovedí venerdí sabato
 2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3 Jabot Manre Juje Wonje Taije Balaire Jarere
 5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
 2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2 sfndag mandag tirsdag onsdag torsdag fredag lfrdag
 7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
 4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
 2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
 2 Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
 2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2 domingo lunes martes miércoles jueves viernes sábado
 2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2 söndag måndag tisdag onsdag torsdag fredag lordag
 2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
 7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
 2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
 6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2 zuntik montik dinstik mitvokh donershtik fraytik shabes
 7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
 2 Sun Moon Mars Mercury Jove Venus Saturn
 2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
 7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
 2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

C

Translation of: C#

<lang c>#include <stdio.h>

  1. include <stdlib.h>
  2. include <string.h>

void process(int lineNum, char buffer[]) {

   char days[7][64];
   int i = 0, d = 0, j = 0;
   while (buffer[i] != 0) {
       if (buffer[i] == ' ') {
           days[d][j] = '\0';
           ++d;
           j = 0;
       } else if (buffer[i] == '\n' || buffer[i] == '\r') {
           days[d][j] = '\0';
           ++d;
           break;
       } else {
           days[d][j] = buffer[i];
           ++j;
       }
       if (d >= 7) {
           printf("There aren't 7 days in line %d\n", lineNum);
           return;
       }
       ++i;
   }
   if (buffer[i] == '\0') {
       days[d][j] = '\0';
       ++d;
   }
   if (d < 7) {
       printf("There aren't 7 days in line %d\n", lineNum);
       return;
   } else {
       int len = 0;
       for (len = 1; len < 64; ++len) {
           int d1;
           for (d1 = 0; d1 < 7; ++d1) {
               int d2;
               for (d2 = d1 + 1; d2 < 7; ++d2) {
                   int unique = 0;
                   for (i = 0; i < len; ++i) {
                       if (days[d1][i] != days[d2][i]) {
                           unique = 1;
                           break;
                       }
                   }
                   if (!unique) {
                       goto next_length;
                   }
               }
           }
           // uniqueness found for this length
           printf("%2d ", len);
           for (i = 0; i < 7; ++i) {
               printf(" %s", days[i]);
           }
           printf("\n");
           return;
           // a duplication was found at the current length
       next_length: {}
       }
   }
   printf("Failed to find uniqueness within the bounds.");

}

int main() {

   char buffer[1024];
   int lineNum = 1, len;
   FILE *fp;
   fp = fopen("days_of_week.txt", "r");
   while (1) {
       memset(buffer, 0, sizeof(buffer));
       fgets(buffer, sizeof(buffer), fp);
       len = strlen(buffer);
       if (len == 0 || buffer[len - 1] == '\0') {
           break;
       }
       process(lineNum++, buffer);
   }
   fclose(fp);
   return 0;

}</lang>

Output:
 2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4  E_djelδ E_hδnδ E_martδ E_mδrkurδ E_enjte E_premte E_shtunδ
 2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2  domingu llunes martes miΘrcoles xueves vienres sßbadu
 2  Bazar_g▄n▄ Birinci_g▄n ╟kinci_g▄n ▄τ▄nc▄_g▄n D╓rd▄nc▄_g▄n Bes,inci_g▄n Alt≥nc≥_g▄n
 6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2  Dimanch Lendi Madi MΦkredi Jedi Vandredi Samdi
 2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2  nede^le ponde^lφ ·ter  str^eda c^tvrtek pßtek sobota
 2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  Diman^co Lundo Mardo Merkredo ^Ja∙do Vendredo Sabato
 1  p▄hapΣev esmaspΣev teisipΣev kolmapΣev neljapΣev reede laupΣev
There aren't 7 days in line 26
 7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2  sunnudagur mßnadagur t sdaguy mikudagur h≤sdagur friggjadagur leygardagur
 2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2  dimanche lundi mardi mercredi jeudi vendredi samedi
 4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2  Domingo Segunda_feira Martes MΘrcores Joves Venres Sßbado
 2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6  p≤pule p≤`akahi p≤`alua p≤`akolu p≤`ahß p≤`alima p≤`aono
 7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3  vasßrnap hΘtf÷ kedd szerda csⁿt÷rt÷k pΘntek szombat
 2  Sunnudagur Mßnudagur ªridjudagur Midvikudagar Fimmtudagur F╓studagur Laugardagur
 2  sundio lundio mardio merkurdio jovdio venerdio saturdio
 3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4  DΘ_Domhnaigh DΘ_Luain DΘ_Mßirt DΘ_Ceadaoin DΘ_ardaoin DΘ_hAoine DΘ_Sathairn
 2  domenica lunedφ martedφ mercoledφ giovedφ venerdφ sabato
 2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7  Dies_Dominica Dies_Lunµ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12  xing-_qi-_r∞ xing-_qi-_yi-. xing-_qi-_Φr xing-_qi-_san-. xing-_qi-_s∞ xing-_qi-_wuv. xing-_qi-_li∙
 3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3  Jabot Manre Juje Wonje Taije Balaire Jarere
 5  geminrongo min≥mishi mßrtes miΦrkoles misheushi bΦrnashi mishßbaro
 2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2  sfndag mandag tirsdag onsdag torsdag fredag lfrdag
 7  lo_dimenge lo_diluns lo_dimarτ lo_dimΦrcres lo_dij≥us lo_divendres lo_dissabte
 4  djadomingo djaluna djamars djarason djaweps djabiΦrna djasabra
 2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3  Domingo segunda-feire terτa-feire quarta-feire quinta-feire sexta-feira sσbado
 1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2  Duminic¬ Luni Mart'i Miercuri Joi Vineri SΓmb¬t¬
 2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4  Sunday Di-luain Di-mαirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2  domingo lunes martes miΘrcoles jueves viernes sßbado
 2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2  s÷ndag mσndag tisdag onsdag torsdag fredag lordag
 2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6  LΘ-pαi-jφt Pαi-it Pαi-j∩ Pαi-sa± Pαi-s∞ Pαi-g╓. Pαi-lßk
 7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6  Pazar Pazartesi Sali ╟ar,samba Per,sembe Cuma Cumartesi
 2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8  Chu?_NhΓ.t Th·*_Hai Th·*_Ba Th·*_Tu* Th·*_Na'm Th·*_Sßu Th·*_Ba?y
 6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2  zuntik montik dinstik mitvokh donershtik fraytik shabes
 7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7  Dies_Dominica Dies_Lunµ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11  Bazar_g▄n▄ Bazar_µrtµsi ╟µrs,µnbµ_axs,am≥ ╟µrs,µnbµ_g▄n▄ C▄mµ_axs,am≥ C▄mµ_g▄n▄ C▄mµ_Senbµ
 2  Sun Moon Mars Mercury Jove Venus Saturn
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1  Domingo Luns Terza_feira Corta_feira Xoves Venres Sßbado
 7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12  xing-_qi-_tiαn xing-_qi-_yi-. xing-_qi-_Φr xing-_qi-_san-. xing-_qi-_s∞ xing-_qi-_wuv. xing-_qi-_li∙
 4  djadomingu djaluna djamars djarason djaweps djabiΦrnΦ djasabra
 2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

C#

<lang csharp>using System; using System.Collections.Generic;

namespace Abbreviations {

   class Program {
       static void Main(string[] args) {
           string[] lines = System.IO.File.ReadAllLines("days_of_week.txt");
           int i = 0;
           foreach (string line in lines) {
               i++;
               if (line.Length > 0) {
                   var days = line.Split();
                   if (days.Length != 7) {
                       throw new Exception("There aren't 7 days in line " + i);
                   }
                   Dictionary<string, int> temp = new Dictionary<string, int>();
                   foreach (string day in days) {
                       if (temp.ContainsKey(day)) {
                           Console.WriteLine(" ∞  {0}", line);
                           continue;
                       }
                       temp.Add(day, 1);
                   }
                   int len = 1;
                   while (true) {
                       temp.Clear();
                       foreach(string day in days) {
                           string key;
                           if (len < day.Length) {
                               key = day.Substring(0, len);
                           } else {
                               key = day;
                           }
                           if (temp.ContainsKey(key)) {
                               break;
                           }
                           temp.Add(key, 1);
                       }
                       if (temp.Count == 7) {
                           Console.WriteLine("{0,2:D}  {1}", len, line);
                           break;
                       }
                       len++;
                   }
               }
           }
       }
   }

}</lang>

Output:
 2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4  E_djel‰ E_h‰n‰ E_mart‰ E_m‰rkur‰ E_enjte E_premte E_shtun‰
 2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2  domingu llunes martes mi‚rcoles xueves vienres s badu
 2  Bazar_gšnš Birinci_gšn €kinci_gšn š‡šncš_gšn D™rdšncš_gšn Bes,inci_gšn Alt•nc•_gšn
 6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2  Dimanch Lendi Madi MŠkredi Jedi Vandredi Samdi
 2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2  nede^le ponde^l¡ £ter˜ str^eda c^tvrtek p tek sobota
 2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  Diman^co Lundo Mardo Merkredo ^Ja—do Vendredo Sabato
 1  pšhap„ev esmasp„ev teisip„ev kolmap„ev neljap„ev reede laup„ev
 7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2  sunnudagur m nadagur t˜sdaguy mikudagur h¢sdagur friggjadagur leygardagur
 2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2  dimanche lundi mardi mercredi jeudi vendredi samedi
 4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2  Domingo Segunda_feira Martes M‚rcores Joves Venres S bado
 2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6  p¢pule p¢`akahi p¢`alua p¢`akolu p¢`ah  p¢`alima p¢`aono
 7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3  vas rnap h‚tf” kedd szerda cs�t”rt”k p‚ntek szombat
 2  Sunnudagur M nudagur Æriëjudagur Miëvikudagar Fimmtudagur F™studagur Laugardagur
 2  sundio lundio mardio merkurdio jovdio venerdio saturdio
 3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4  D‚_Domhnaigh D‚_Luain D‚_M irt D‚_Ceadaoin D‚_ardaoin D‚_hAoine D‚_Sathairn
 2  domenica luned¡ marted¡ mercoled¡ gioved¡ venerd¡ sabato
 2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7  Dies_Dominica Dies_Lun‘ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12  xing-_qi-_r� xing-_qi-_yi-. xing-_qi-_Šr xing-_qi-_san-. xing-_qi-_s� xing-_qi-_wuv. xing-_qi-_li—
 3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3  Jabot Manre Juje Wonje Taije Balaire Jarere
 5  geminrongo min•mishi m rtes miŠrkoles misheushi bŠrnashi mish baro
 2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2  síndag mandag tirsdag onsdag torsdag fredag lírdag
 7  lo_dimenge lo_diluns lo_dimar‡ lo_dimŠrcres lo_dij•us lo_divendres lo_dissabte
 4  djadomingo djaluna djamars djarason djaweps djabiŠrna djasabra
 2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3  Domingo segunda-feire ter‡a-feire quarta-feire quinta-feire sexta-feira s†bado
 1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2  Duminic¦ Luni Mart'i Miercuri Joi Vineri Sƒmb¦t¦
 2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4  Sunday Di-luain Di-m…irt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2  domingo lunes martes mi‚rcoles jueves viernes s bado
 2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2  s”ndag m†ndag tisdag onsdag torsdag fredag lordag
 2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6  L‚-p…i-j¡t P…i-it P…i-j‹ P…i-sa¤ P…i-s� P…i-g™. P…i-l k
 7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6  Pazar Pazartesi Sali €ar,samba Per,sembe Cuma Cumartesi
 2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8  Chu?_Nhƒ.t Th£*_Hai Th£*_Ba Th£*_Tu* Th£*_Na'm Th£*_S u Th£*_Ba?y
 6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2  zuntik montik dinstik mitvokh donershtik fraytik shabes
 7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7  Dies_Dominica Dies_Lun‘ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11  Bazar_gšnš Bazar_‘rt‘si €‘rs,‘nb‘_axs,am• €‘rs,‘nb‘_gšnš Cšm‘_axs,am• Cšm‘_gšnš Cšm‘_Senb‘
 2  Sun Moon Mars Mercury Jove Venus Saturn
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1  Domingo Luns Terza_feira Corta_feira Xoves Venres S bado
 7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12  xing-_qi-_ti…n xing-_qi-_yi-. xing-_qi-_Šr xing-_qi-_san-. xing-_qi-_s� xing-_qi-_wuv. xing-_qi-_li—
 4  djadomingu djaluna djamars djarason djaweps djabiŠrnŠ djasabra
 2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

C++

Translation of: C#

<lang cpp>#include <iomanip>

  1. include <iostream>
  2. include <fstream>
  3. include <map>
  4. include <sstream>
  5. include <string>
  6. include <vector>

std::vector<std::string> split(const std::string& str, char delimiter) {

   std::vector<std::string> tokens;
   std::string token;
   std::istringstream tokenStream(str);
   while (std::getline(tokenStream, token, delimiter)) {
       tokens.push_back(token);
   }
   return tokens;

}

int main() {

   using namespace std;
   string line;
   int i = 0;
   ifstream in("days_of_week.txt");
   if (in.is_open()) {
       while (getline(in, line)) {
           i++;
           if (line.empty()) {
               continue;
           }
           auto days = split(line, ' ');
           if (days.size() != 7) {
               throw std::runtime_error("There aren't 7 days in line " + i);
           }
           map<string, int> temp;
           for (auto& day : days) {
               if (temp.find(day) != temp.end()) {
                   cerr << " ∞  " << line << '\n';
                   continue;
               }
               temp[day] = 1;
           }
           int len = 1;
           while (true) {
               temp.clear();
               for (auto& day : days) {
                   string key = day.substr(0, len);
                   if (temp.find(key) != temp.end()) {
                       break;
                   }
                   temp[key] = 1;
               }
               if (temp.size() == 7) {
                   cout << setw(2) << len << "  " << line << '\n';
                   break;
               }
               len++;
           }
       }
   }
   return 0;

}</lang>

Output:
 2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4  E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
 2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2  domingu llunes martes miércoles xueves vienres sábadu
 2  Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
 6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2  Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
 2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2  nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
 2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
 1  pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
 7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2  sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
 2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2  dimanche lundi mardi mercredi jeudi vendredi samedi
 4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2  Domingo Segunda_feira Martes Mércores Joves Venres Sábado
 2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 7  pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
 7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3  vasárnap hétfö kedd szerda csütörtök péntek szombat
 2  Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
 2  sundio lundio mardio merkurdio jovdio venerdio saturdio
 3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 5  Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
 2  domenica lunedí martedí mercoledí giovedí venerdí sabato
 2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12  xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3  Jabot Manre Juje Wonje Taije Balaire Jarere
 5  geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
 2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2  sφndag mandag tirsdag onsdag torsdag fredag lφrdag
 7  lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
 4  djadomingo djaluna djamars djarason djaweps djabièrna djasabra
 2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3  Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
 1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2  Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
 2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4  Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2  domingo lunes martes miércoles jueves viernes sábado
 2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2  söndag måndag tisdag onsdag torsdag fredag lordag
 2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 7  Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
 7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6  Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
 2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 9  Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
 6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2  zuntik montik dinstik mitvokh donershtik fraytik shabes
 7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
15  Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
 2  Sun Moon Mars Mercury Jove Venus Saturn
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1  Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
 7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12  xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 4  djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
 2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Common Lisp

It uses the standard library split-sequence to split the string into words. <lang lisp> (defun max-mismatch (list)

 (if (cdr list)
   (max (apply #'max (mapcar #'(lambda (w2) (mismatch (car list) w2)) (cdr list))) (max-mismatch (cdr list)))
   0 ))

(with-open-file (f "days-of-the-week.txt" :direction :input)

 (do* ((row (read-line f nil nil) (read-line f nil nil)))
      ((null row) t)
   (format t "~d ~a~%" (1+ (max-mismatch (SPLIT-SEQUENCE:split-sequence #\Space row))) row) ))

</lang>

Output:
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2 domingu llunes martes miércoles xueves vienres sábadu
2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
1 
7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
2 dimanche lundi mardi mercredi jeudi vendredi samedi
4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
3 vasárnap hétfö kedd szerda csütörtök péntek szombat
2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
2 sundio lundio mardio merkurdio jovdio venerdio saturdio
3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
2 domenica lunedí martedí mercoledí giovedí venerdí sabato
2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
3 Jabot Manre Juje Wonje Taije Balaire Jarere
5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
1 Domingo Lunes martes Miercoles Jueves Viernes Sabado
2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
2 domingo lunes martes miércoles jueves viernes sábado
2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
2 söndag måndag tisdag onsdag torsdag fredag lordag
2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
2 zuntik montik dinstik mitvokh donershtik fraytik shabes
7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
2 Sun Moon Mars Mercury Jove Venus Saturn
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau
T

D

Translation of: Kotlin

<lang D>import std.conv; import std.exception; import std.range; import std.stdio; import std.string;

void main() {

   foreach (size_t i, dstring line; File("days_of_week.txt").lines) {
       line = chomp(line);
       if (!line.empty) {
           auto days = line.split;
           enforce(days.length==7, text("There aren't 7 days in line ", i+1));
           int[dstring] temp;
           foreach(day; days) {
               temp[day]++;
           }
           if (days.length < 7) {
               writeln(" ∞  ", line);
               continue;
           }
           int len = 1;
           while (true) {
               temp.clear();
               foreach (day; days) {
                   temp[day.take(len).array]++;
               }
               if (temp.length == 7) {
                   writefln("%2d  %s", len, line);
                   break;
               }
               len++;
           }
       }
   }

}</lang>

Output:
 2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4  E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
 2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2  domingu llunes martes miércoles xueves vienres sábadu
 2  Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
 6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2  Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
 2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2  nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
 2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
 1  pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
 7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2  sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
 2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2  dimanche lundi mardi mercredi jeudi vendredi samedi
 4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2  Domingo Segunda_feira Martes Mércores Joves Venres Sábado
 2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6  pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
 7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3  vasárnap hétfö kedd szerda csütörtök péntek szombat
 2  Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
 2  sundio lundio mardio merkurdio jovdio venerdio saturdio
 3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4  Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
 2  domenica lunedí martedí mercoledí giovedí venerdí sabato
 2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12  xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3  Jabot Manre Juje Wonje Taije Balaire Jarere
 5  geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
 2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2  sφndag mandag tirsdag onsdag torsdag fredag lφrdag
 7  lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
 4  djadomingo djaluna djamars djarason djaweps djabièrna djasabra
 2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3  Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
 1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2  Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
 2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4  Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2  domingo lunes martes miércoles jueves viernes sábado
 2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2  söndag måndag tisdag onsdag torsdag fredag lordag
 2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6  Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
 7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6  Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
 2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8  Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
 6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2  zuntik montik dinstik mitvokh donershtik fraytik shabes
 7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11  Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
 2  Sun Moon Mars Mercury Jove Venus Saturn
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1  Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
 7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12  xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 4  djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
 2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Delphi

This example does not show the output mentioned in the task description on this page (or a page linked to from here). Please ensure that it meets all task requirements and remove this message.
Note that phrases in task descriptions such as "print and display" and "print and show" for example, indicate that (reasonable length) output be a part of a language's solution.


Translation of: Kotlin

<lang Delphi> program Abbreviations_Automatic;

{$APPTYPE CONSOLE}

uses

 System.SysUtils,
 System.Generics.Collections,
 System.IOUtils;

function DistinctStrings(strs: TArray<string>): TArray<string>; begin

 var l := length(strs);
 var _set := TDictionary<string, Boolean>.Create;
 SetLength(result, 0);
 for var str in strs do
 begin
   if not _set.ContainsKey(str) then
   begin
     SetLength(result, Length(result) + 1);
     result[High(result)] := str;
     _set.AddOrSetValue(str, true);
   end;
 end;
 _set.free;

end;

function takeRunes(s: string; n: Integer): string; begin

 var i := 0;
 for var j := 0 to s.Length - 1 do
 begin
   if i = n then
     exit(s.Substring(0, j));
   inc(i);
 end;
 Result := s;

end;

begin

 var lines := TFile.ReadAllLines('days_of_week.txt');
 var lineCount := 0;
 while lineCount < length(Lines) do
 begin
   var line := lines[lineCount].Trim;
   inc(lineCount);
   if line.IsEmpty then
   begin
     Writeln;
     Continue;
   end;
   var days := line.Split([' '], TStringSplitOptions.ExcludeEmpty);
   var daysLen := Length(days);
   if daysLen <> 7 then
   begin
     Writeln('There arent 7 days in line', lineCount);
     Readln;
     halt;
   end;
   if Length(distinctStrings(days)) <> 7 then
   begin
     writeln(' infinity ', line);
     Continue;
   end;
   var abbrevLen := 0;
   while True do
   begin
     var abbrevs: TArray<string>;
     SetLength(abbrevs, daysLen);
     for var i := 0 to daysLen - 1 do
       abbrevs[i] := takeRunes(days[i], abbrevLen);
     if Length(distinctStrings(abbrevs)) = 7 then
     begin
       Writeln(abbrevLen.ToString.PadLeft(2).PadRight(3), line);
       Break;
     end;
     inc(abbrevLen);
   end;
 end;
 Readln;

end.</lang>

Erlang

This example uses a byproduct of turning a list into a set. Only the unique elements are added to the set.

The output is of the set of abbreviations. These are not sorted correctly and some encoding errors remain.

<lang erlang> -module(abbreviateweekdays). -export([ main/0 ]).


uniq(L,Acc) ->

   io:fwrite("Min = ~p",[Acc]),
   io:fwrite(" Abbr:~p~n",[ sets:to_list(L) ]).

uniq(_, L, Acc) ->

   Abbr = [string:substr(X,1,Acc) || X <- L],
   %  list of abbrevs, starting with substring 1,1:
   TempSet = sets:from_list( Abbr ),
   TempSize = sets:size(TempSet),
   if 
     TempSize =:= 7 -> 
       uniq(TempSet,Acc);
     true  -> uniq(0, L, Acc+1)
    end.

read_lines(Device, Acc) when Acc < 19 ->

  case file:read_line(Device) of
   {ok, Line} ->
     Tokenized = string:tokens(Line," "),
     uniq(0,Tokenized,1),
     read_lines(Device, Acc + 1);
    eof ->
      io:fwrite("~p~n",["Done"])
   end;

read_lines(Device, 19) ->

      io:fwrite("~p~n",["Done"]).
   

main() ->

 {ok, Device} = (file:open("weekdays.txt", read)),
 read_lines(Device, 1).

</lang>

Output:
40> c(abbreviateweekdays).
abbreviateweekdays.erl:28: Warning: variable 'Device' is unused
{ok,abbreviateweekdays}
41> abbreviateweekdays:main().
Min = 2 Abbr:["Th","Sa","Tu","Su","Mo","We","Fr"]
Min = 2 Abbr:["Sa","Ma","Do","Di","So","Wo","Vr"]
Min = 4 Abbr:["E_ma","E_sh","E_dj","E_hÃ","E_en","E_mÃ","E_pr"]
Min = 2 Abbr:["Eh","Er","Ha","Ma","Se","Ar","Ke"]
Min = 5 Abbr:["Al_Ka","Al_Ah","Al_Go","Al_Ar","Al_It","Al_Th","Al_Sa"]
Min = 4 Abbr:["Yerg","Shap","Yere","Hink","Guir","Tcho","Ourp"]
Min = 2 Abbr:["vi","ma","do","xu","mi","sÃ","ll"]
Min = 2 Abbr:["Al",[195,135],"Ba",[195,156],"DÃ","Be","Bi"]
Min = 6 Abbr:["Astele","Astear","Ostira","Ostegu","Larunb","Igande","Asteaz"]
Min = 4 Abbr:["Robi","Mong","Budh","BRih","Shom","Shuk","Shon"]
Min = 2 Abbr:["Pe","Po","Ne","Cx","Su","Sr","Ut"]
Min = 5 Abbr:["Disad","Dilun","Diria","Digwe","Dimeu","Disul","Dimer"]
Min = 2 Abbr:["pe","po","sa","ne","ch","sr","vt"]
Min = 12 Abbr:["sing_kei_saa","sing_kei_yah","sing_kei_luk","sing_kei_yee",
       "sing_kei_ng","sing_kei_sie","sing_kei_yat"]
Min = 4 Abbr:["Dill","Dijo","Dima","Dium","Dime","Diss","Dive"]
Min = 16 Abbr:["Tl-oowey_tts-el_","Dzeehn_kk-ehreh","Tah_neesee_dzeeh",
       "Dzeentt-ahzee\n","Dzeenkk-eh","Dzeehn_kk-ehreh_","Deehn_ghee_dzee-"]
Min = 6 Abbr:["dy_Gwe","dy_You","dy_Meu","dy_Sul","dy_Mer","dy_Sad","dy_Lun"]
Min = 2 Abbr:["Je","Sa","Ma","Di","Va","Le","MÃ"]
"Done"
ok

F#

The function

<lang fsharp> let fN g=let rec fN n=if g|>List.map(fun(g:string)->g.[0..n])|>Set.ofList|>Set.count=(List.length g) then (n+1) else fN(n+1)

        fN 0

</lang>

The Task - Demonstrate the function

<lang fsharp> fN ["Sunday"; "Monday"; "Tuesday"; "Wednesday"; "Thursday"; "Friday"; "Saturday"] // -> 2 fN ["Sondag"; "Maandag"; "Dinsdag"; "Woensdag"; "Donderdag"; "Vrydag"; "Saterdag"] // -> 2 fN ["E_djelë"; "E_hënë"; "E_martë"; "E_mërkurë"; "E_enjte"; "E_premte"; "E_shtunë"] // -> 4 fN ["Ehud"; "Segno"; "Maksegno"; "Erob"; "Hamus"; "Arbe"; "Kedame"] // -> 2 fN ["Al_Ahad"; "Al_Ithinin"; "Al_Tholatha'a"; "Al_Arbia'a"; "Al_Kamis"; "Al_Gomia'a"; "Al_Sabit";] // -> 5 </lang>

Factor

Part of Factor's philosophy is to write extremely short words (functions). As a guideline, words should usually fit on one to three 64-column lines unless they use cond or contain a large literal. If you find yourself writing a word longer than that, it's time to factor!

As a concatenative language, Factor is uniquely suited for factoring words into smaller words. Assuming lexical/dynamic variables are not used, factoring is a cut-and-paste job that can be performed almost anywhere there is whitespace.

<lang factor>USING: formatting io io.encodings.utf8 io.files kernel math sequences sets splitting ; IN: rosetta-code.abbreviations-automatic

map-head ( seq n -- seq' ) [ short head ] curry map ;
unique? ( seq n -- ? ) map-head all-unique? ;
(abbr-length) ( seq -- n )
   1 [ 2dup unique? ] [ 1 + ] until nip ;
abbr-length ( str -- n/str )
   [ "" ] [ " " split (abbr-length) ] if-empty ;
show ( str -- ) dup abbr-length swap " %2u %s\n" printf ;
labels ( -- )
   "Min." "abbr" "Days of the week" "%s\n%s%32s\n" printf ;
line ( n -- ) [ "=" write ] times ;
header ( -- ) labels 4 line bl 75 line nl ;
body ( -- ) [ show ] each-line ;
abbreviations ( -- )
   header "day-names.txt" utf8 [ body ] with-file-reader ;

MAIN: abbreviations</lang>

Output:
Min.
abbr                Days of the week
==== ===========================================================================
  2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
  2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
  4  E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
  2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
  5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
  4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
  2  domingu llunes martes miércoles xueves vienres sábadu
  2  Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
  6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
  4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
  2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
  5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
  2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
 12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
  4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
 16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
  6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
  2  Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
  2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
  2  nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
  2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
  2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
  2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
  2  Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
  1  pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
 ""  
  7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
  2  sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
  2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
  2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
  2  dimanche lundi mardi mercredi jeudi vendredi samedi
  4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
  2  Domingo Segunda_feira Martes Mércores Joves Venres Sábado
  2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
  2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
  2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
  3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
  6  pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
  7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
  3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
  3  vasárnap hétfö kedd szerda csütörtök péntek szombat
  2  Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
  2  sundio lundio mardio merkurdio jovdio venerdio saturdio
  3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
  2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
  4  Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
  2  domenica lunedí martedí mercoledí giovedí venerdí sabato
  2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
  1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
  7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
  3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
  2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
  3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
 12  xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
  3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
  3  Jabot Manre Juje Wonje Taije Balaire Jarere
  5  geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
  2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
  2  sφndag mandag tirsdag onsdag torsdag fredag lφrdag
  7  lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
  4  djadomingo djaluna djamars djarason djaweps djabièrna djasabra
  2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
  3  Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
  1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
  2  Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
  2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
  4  Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
  2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
  5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
  2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
  2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
  2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
  2  domingo lunes martes miércoles jueves viernes sábado
  2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
  7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
  2  söndag måndag tisdag onsdag torsdag fredag lordag
  2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
  6  Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
  7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
  5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
  6  Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
  2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
  8  Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
  6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
  3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
  7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
  2  zuntik montik dinstik mitvokh donershtik fraytik shabes
  7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
  7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 11  Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
  2  Sun Moon Mars Mercury Jove Venus Saturn
  2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
  2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
  5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
  1  Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
  7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
 12  xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
  4  djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
  2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Go

Translation of: Kotlin

<lang go>package main

import(

   "bufio"
   "fmt"
   "os"
   "strings"

)

func distinctStrings(strs []string) []string {

   len := len(strs)
   set := make(map[string]bool, len)
   distinct := make([]string, 0, len)
   for _, str := range strs {
       if !set[str] {
           distinct = append(distinct, str)
           set[str] = true
       }
   }
   return distinct

}

func takeRunes(s string, n int) string {

   i := 0
   for j := range s {
       if i == n {
           return s[:j]
       }
       i++
   }
   return s

}

func main() {

   file, err := os.Open("days_of_week.txt")
   if err != nil {
       fmt.Println("Unable to open file.")
       return
   }
   defer file.Close()
   reader := bufio.NewReader(file)
   lineCount := 0
   for {
       line, err := reader.ReadString('\n')
       if err != nil { // end of file reached
           return
       }
       line = strings.TrimSpace(line)
       lineCount++
       if line == "" {
           fmt.Println()
           continue
       }
       days := strings.Fields(line)
       daysLen := len(days)
       if (len(days) != 7) {
           fmt.Println("There aren't 7 days in line", lineCount)
           return
       }
       if len(distinctStrings(days)) != 7 { // implies some days have the same name
           fmt.Println(" ∞ ", line)
           continue
       }
       for abbrevLen := 1; ; abbrevLen++ {
           abbrevs := make([]string, daysLen)
           for i := 0; i < daysLen; i++ {
               abbrevs[i] = takeRunes(days[i], abbrevLen)
           }
           if len(distinctStrings(abbrevs)) == 7 {
               fmt.Printf("%2d  %s\n", abbrevLen, line)
               break
           }
       }
   }

}</lang>

Output:
Same as Kotlin entry.

Groovy

Translation of: Java

<lang groovy>class Abbreviations {

   static void main(String[] args) throws IOException {
       BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream("days_of_week.txt"), "utf-8"))
       List<String> readAllLines = br.readLines()
       for (int i = 0; i < readAllLines.size(); i++) {
           String line = readAllLines.get(i)
           if (line.length() == 0) continue
           String[] days = line.split(" ")
           if (days.length != 7) throw new RuntimeException("There aren't 7 days on line " + (i + 1))
           Map<String, Integer> temp = new HashMap<>()
           for (String day : days) {
               Integer count = temp.getOrDefault(day, 0)
               temp.put(day, count + 1)
           }
           if (temp.size() < 7) {
               System.out.print(" ∞  ")
               System.out.println(line)
               continue
           }
           int len = 1
           while (true) {
               temp.clear()
               for (String day : days) {
                   String sd
                   if (len >= day.length()) {
                       sd = day
                   } else {
                       sd = day.substring(0, len)
                   }
                   Integer count = temp.getOrDefault(sd, 0)
                   temp.put(sd, count + 1)
               }
               if (temp.size() == 7) {
                   System.out.printf("%2d  %s\n", len, line)
                   break
               }
               len++
           }
       }
   }

}</lang>

Output:
 2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4  E_djel� E_h�n� E_mart� E_m�rkur� E_enjte E_premte E_shtun�
 2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2  domingu llunes martes mi�rcoles xueves vienres s�badu
 2  Bazar_g�n� Birinci_g�n �kinci_g�n ���nc�_g�n D�rd�nc�_g�n Bes,inci_g�n Alt�nc�_g�n
 6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2  Dimanch Lendi Madi M�kredi Jedi Vandredi Samdi
 2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2  nede^le ponde^l� �ter� str^eda c^tvrtek p�tek sobota
 2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  Diman^co Lundo Mardo Merkredo ^Ja�do Vendredo Sabato
 1  p�hap�ev esmasp�ev teisip�ev kolmap�ev neljap�ev reede laup�ev
 7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2  sunnudagur m�nadagur t�sdaguy mikudagur h�sdagur friggjadagur leygardagur
 2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2  dimanche lundi mardi mercredi jeudi vendredi samedi
 4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2  Domingo Segunda_feira Martes M�rcores Joves Venres S�bado
 2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6  p�pule p�`akahi p�`alua p�`akolu p�`ah� p�`alima p�`aono
 7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3  vas�rnap h�tf� kedd szerda cs�t�rt�k p�ntek szombat
 2  Sunnudagur M�nudagur �ridjudagur Midvikudagar Fimmtudagur F�studagur Laugardagur
 2  sundio lundio mardio merkurdio jovdio venerdio saturdio
 3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4  D�_Domhnaigh D�_Luain D�_M�irt D�_Ceadaoin D�_ardaoin D�_hAoine D�_Sathairn
 2  domenica luned� marted� mercoled� gioved� venerd� sabato
 2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7  Dies_Dominica Dies_Lun� Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12  xing-_qi-_r� xing-_qi-_yi-. xing-_qi-_�r xing-_qi-_san-. xing-_qi-_s� xing-_qi-_wuv. xing-_qi-_li�
 3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3  Jabot Manre Juje Wonje Taije Balaire Jarere
 5  geminrongo min�mishi m�rtes mi�rkoles misheushi b�rnashi mish�baro
 2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2  sfndag mandag tirsdag onsdag torsdag fredag lfrdag
 7  lo_dimenge lo_diluns lo_dimar� lo_dim�rcres lo_dij�us lo_divendres lo_dissabte
 4  djadomingo djaluna djamars djarason djaweps djabi�rna djasabra
 2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3  Domingo segunda-feire ter�a-feire quarta-feire quinta-feire sexta-feira s�bado
 1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2  Duminic� Luni Mart'i Miercuri Joi Vineri S�mb�t�
 2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4  Sunday Di-luain Di-m�irt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2  domingo lunes martes mi�rcoles jueves viernes s�bado
 2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2  s�ndag m�ndag tisdag onsdag torsdag fredag lordag
 2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6  L�-p�i-j�t P�i-it P�i-j� P�i-sa� P�i-s� P�i-g�. P�i-l�k
 7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6  Pazar Pazartesi Sali �ar,samba Per,sembe Cuma Cumartesi
 2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8  Chu?_Nh�.t Th�*_Hai Th�*_Ba Th�*_Tu* Th�*_Na'm Th�*_S�u Th�*_Ba?y
 6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2  zuntik montik dinstik mitvokh donershtik fraytik shabes
 7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7  Dies_Dominica Dies_Lun� Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11  Bazar_g�n� Bazar_�rt�si ��rs,�nb�_axs,am� ��rs,�nb�_g�n� C�m�_axs,am� C�m�_g�n� C�m�_Senb�
 2  Sun Moon Mars Mercury Jove Venus Saturn
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1  Domingo Luns Terza_feira Corta_feira Xoves Venres S�bado
 7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12  xing-_qi-_ti�n xing-_qi-_yi-. xing-_qi-_�r xing-_qi-_san-. xing-_qi-_s� xing-_qi-_wuv. xing-_qi-_li�
 4  djadomingu djaluna djamars djarason djaweps djabi�rn� djasabra
 2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Haskell

<lang haskell>import Data.List (inits, intercalate, nub, transpose)

-- ABBREVIATIONS ------------------------------------------ abbrevns :: [String] -> [String] abbrevns xs

 | null xs = []
 | otherwise =
   let n = length xs
   in head $ dropWhile ((< n) . length) $ nub <$> transpose (inits <$> xs)

-- TEST --------------------------------------------------- main :: IO () main = do

 s <- readFile "./weekDayNames.txt"
 mapM_ putStrLn $
   take 10 $
   (\xs ->
       intercalate "\t" $
       [show . length . head . abbrevns . words, id] <*> [xs]) <$>
   lines s</lang>
Output:
2    Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2    Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4    E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2    Ehud Segno Maksegno Erob Hamus Arbe Kedame
5    Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4    Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2    domingu llunes martes miércoles xueves vienres sábadu
2    Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6    Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4    Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar

J

<lang> NB. y is words in boxes abbreviation_length =: monad define

N =. # y
for_i. i. >: >./ #&> y do.
 NB. if the length of the set of length i prefixes matches the length of the row
 if. N -: # ~. i ({. &>) y do.
  i return.
 end.
end.

)

NB. use: auto_abbreviate DAY_NAMES auto_abbreviate =: 3 :0

y =. y -. CR
lines =. [;._2 y
a =. <@([: <;._2 ,&' ');._2 y
L =. abbreviation_length&> a
((' ',~":)&> L) ,"1 lines

) </lang>


   DAY_NAMES =: noun define
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë

Ehud Segno Maksegno Erob Hamus Arbe Kedame
Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
)

   auto_abbreviate DAY_NAMES
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday                
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag               
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë              
0                                                                         
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame                              
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit

Java

Translation of: D

<lang Java>import java.io.IOException; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.util.HashMap; import java.util.List; import java.util.Map;

public class Abbreviations {

   public static void main(String[] args) throws IOException {
       Path path = Paths.get("days_of_week.txt");
       List<String> readAllLines = Files.readAllLines(path);
       for (int i = 0; i < readAllLines.size(); i++) {
           String line = readAllLines.get(i);
           if (line.length() == 0) continue;
           String[] days = line.split(" ");
           if (days.length != 7) throw new RuntimeException("There aren't 7 days on line " + (i + 1));
           Map<String, Integer> temp = new HashMap<>();
           for (String day : days) {
               Integer count = temp.getOrDefault(day, 0);
               temp.put(day, count + 1);
           }
           if (temp.size() < 7) {
               System.out.print(" ∞  ");
               System.out.println(line);
               continue;
           }
           int len = 1;
           while (true) {
               temp.clear();
               for (String day : days) {
                   String sd;
                   if (len >= day.length()) {
                       sd = day;
                   } else {
                       sd = day.substring(0, len);
                   }
                   Integer count = temp.getOrDefault(sd, 0);
                   temp.put(sd, count + 1);
               }
               if (temp.size() == 7) {
                   System.out.printf("%2d  %s\n", len, line);
                   break;
               }
               len++;
           }
       }
   }

}</lang>

Output:
 2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4  E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
 2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2  domingu llunes martes miércoles xueves vienres sábadu
 2  Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
 6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2  Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
 2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2  nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
 2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
 1  pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
 7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2  sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
 2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2  dimanche lundi mardi mercredi jeudi vendredi samedi
 4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2  Domingo Segunda_feira Martes Mércores Joves Venres Sábado
 2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6  pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
 7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3  vasárnap hétfö kedd szerda csütörtök péntek szombat
 2  Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
 2  sundio lundio mardio merkurdio jovdio venerdio saturdio
 3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4  Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
 2  domenica lunedí martedí mercoledí giovedí venerdí sabato
 2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12  xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3  Jabot Manre Juje Wonje Taije Balaire Jarere
 5  geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
 2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2  sφndag mandag tirsdag onsdag torsdag fredag lφrdag
 7  lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
 4  djadomingo djaluna djamars djarason djaweps djabièrna djasabra
 2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3  Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
 1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2  Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
 2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4  Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2  domingo lunes martes miércoles jueves viernes sábado
 2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2  söndag måndag tisdag onsdag torsdag fredag lordag
 2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6  Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
 7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6  Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
 2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8  Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
 6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2  zuntik montik dinstik mitvokh donershtik fraytik shabes
 7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11  Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
 2  Sun Moon Mars Mercury Jove Venus Saturn
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1  Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
 7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12  xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 4  djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
 2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Julia

<lang julia>const text = """ Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë Ehud Segno Maksegno Erob Hamus Arbe Kedame Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat domingu llunes martes miércoles xueves vienres sábadu Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn nedelia ponedelnik vtornik sriada chetvartak petak sabota sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee s0ndag mandag tirsdag onsdag torsdag fredag l0rdag zondag maandag dinsdag woensdag donderdag vrijdag zaterdag Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai dimanche lundi mardi mercredi jeudi vendredi samedi Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon Domingo Segunda_feira Martes Mércores Joves Venres Sábado k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar vasárnap hétfö kedd szerda csütörtök péntek szombat Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur sundio lundio mardio merkurdio jovdio venerdio saturdio Minggu Senin Selasa Rabu Kamis Jumat Sabtu Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn domenica lunedí martedí mercoledí giovedí venerdí sabato Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam Jabot Manre Juje Wonje Taije Balaire Jarere geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu sφndag mandag tirsdag onsdag torsdag fredag lφrdag lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte djadomingo djaluna djamars djarason djaweps djabièrna djasabra Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado Domingo Lunes martes Miercoles Jueves Viernes Sabado Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne nedjelja ponedjeljak utorak sreda cxetvrtak petak subota Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha- nedel^a pondelok utorok streda s^tvrtok piatok sobota Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota domingo lunes martes miércoles jueves viernes sábado sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi söndag måndag tisdag onsdag torsdag fredag lordag Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi nedilya ponedilok vivtorok sereda chetver pyatnytsya subota Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo zuntik montik dinstik mitvokh donershtik fraytik shabes iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ Sun Moon Mars Mercury Jove Venus Saturn zondag maandag dinsdag woensdag donderdag vrijdag zaterdag KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù djadomingu djaluna djamars djarason djaweps djabièrnè djasabra Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau"""

function processweek(txt)

   for lin in split(txt, "\n")
       print(lin)
       if length(lin) < 7
           println("A blank line returns \"\", a blank string.")
           continue
       end
       words = map(x->"$x", split(lin, r"\s+"))
       minlen = minimum(map(length, words))
       abbrev = fill("", length(words))
       for i in 1:minlen
           if length(unique(wrd -> split(wrd, "")[1:i], words)) == length(words)
               for (k, word) in enumerate(words)
                   abbrev[k] = join(split(word, "")[1:i], "")
               end
               println(" => ", abbrev, ", which are length ", i)
               break
           elseif i == minlen 
               println(" => Could not find abbreviations for the week")
           end
       end
   end

end

processweek(text)

</lang>

Output:

(Showing first 10 lines.) Sunday Monday Tuesday Wednesday Thursday Friday Saturday => ["Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"], which are length 2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag => ["So", "Ma", "Di", "Wo", "Do", "Vr", "Sa"], which are length 2 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë => ["E_dj", "E_hë", "E_ma", "E_më", "E_en", "E_pr", "E_sh"], which are length 4 Ehud Segno Maksegno Erob Hamus Arbe Kedame => ["Eh", "Se", "Ma", "Er", "Ha", "Ar", "Ke"], which are length 2 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit => ["Al_Ah", "Al_It", "Al_Th", "Al_Ar", "Al_Ka", "Al_Go", "Al_Sa"], which are length 5 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat => ["Guir", "Yerg", "Yere", "Tcho", "Hink", "Ourp", "Shap"], which are length 4 domingu llunes martes miércoles xueves vienres sábadu => ["do", "ll", "ma", "mi", "xu", "vi", "sá"], which are length 2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn => ["Ba", "Bi", "Çk", "Üç", "DÖ", "Be", "Al"], which are length 2 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat => ["Igande", "Astele", "Astear", "Asteaz", "Ostegu", "Ostira", "Larunb"], which are length 6 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar => ["Robi", "Shom", "Mong", "Budh", "BRih", "Shuk", "Shon"], which are length 4

Kotlin

Original O(n2) solution

where n is the number of strings in each line. <lang scala>// version 1.1.4-3

import java.io.File

val r = Regex("[ ]+")

fun main(args: Array<String>) {

   val lines = File("days_of_week.txt").readLines()
   for ((i, line) in lines.withIndex()) {
       if (line.trim().isEmpty()) {
           println()
           continue
       }
       val days = line.trim().split(r)
       if (days.size != 7) throw RuntimeException("There aren't 7 days in line ${i + 1}")
       if (days.distinct().size < 7) { // implies some days have the same name
           println(" ∞  $line")
           continue
       }
       var len = 1
       while (true) {
           if (days.map { it.take(len) }.distinct().size ==  7) {
               println("${"%2d".format(len)}  $line")
               break
           }
           len++
       }
   }  

}</lang>

Output:
 2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4  E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
 2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2  domingu llunes martes miércoles xueves vienres sábadu
 2  Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
 6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2  Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
 2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2  nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
 2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
 1  pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
    
 7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2  sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
 2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2  dimanche lundi mardi mercredi jeudi vendredi samedi
 4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2  Domingo Segunda_feira Martes Mércores Joves Venres Sábado
 2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6  pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
 7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3  vasárnap hétfö kedd szerda csütörtök péntek szombat
 2  Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
 2  sundio lundio mardio merkurdio jovdio venerdio saturdio
 3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4  Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
 2  domenica lunedí martedí mercoledí giovedí venerdí sabato
 2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12  xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3  Jabot Manre Juje Wonje Taije Balaire Jarere
 5  geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
 2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2  sφndag mandag tirsdag onsdag torsdag fredag lφrdag
 7  lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
 4  djadomingo djaluna djamars djarason djaweps djabièrna djasabra
 2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3  Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
 1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2  Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
 2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4  Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2  domingo lunes martes miércoles jueves viernes sábado
 2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2  söndag måndag tisdag onsdag torsdag fredag lordag
 2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6  Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
 7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6  Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
 2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8  Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
 6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2  zuntik montik dinstik mitvokh donershtik fraytik shabes
 7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11  Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
 2  Sun Moon Mars Mercury Jove Venus Saturn
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1  Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
 7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12  xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 4  djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
 2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Alternative O(n log n) solution based on sorting

<lang scala>import java.io.File import kotlin.math.max

fun getMinimumPrefixLength(distinctWords: Iterable<String>): Int {

   return distinctWords
       .sorted()
       .fold(Pair("", 0),
           { (previousWord, minLength), currentWord ->
               val firstNonMatchingIdx = previousWord
                   .asSequence()
                   .zip(currentWord.asSequence())
                   .indexOfFirst { it.first != it.second }
               return@fold Pair(
                   currentWord,
                   max(
                       // firstNonMatchingIdx would be -1 iff  previousWord is a prefix of currentWord
                       if (firstNonMatchingIdx != -1) firstNonMatchingIdx + 1 else previousWord.length + 1,
                       minLength)
               )
           })
       .second

}

fun getMinimumPrefixLength(whitespaceSeparatedDistinctWords: String) =

   getMinimumPrefixLength(whitespaceSeparatedDistinctWords.split(Regex("\\s+")))

fun main() {

   File("/tmp/input.txt").useLines {
       it.map(String::trim)
           .filter(String::isNotEmpty)
           .map({ "${getMinimumPrefixLength(it).toString().padEnd(5)} ${it}" })
           .forEach(::println)
   }

}</lang>

Output:
2     Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2     Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4     E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2     Ehud Segno Maksegno Erob Hamus Arbe Kedame
5     Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4     Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2     domingu llunes martes miércoles xueves vienres sábadu
2     Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6     Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4     Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2     Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5     Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2     nedelia ponedelnik vtornik sriada chetvartak petak sabota
12    sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4     Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16    Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
6     dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
2     Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
2     nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
2     nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
2     Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
2     s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
2     zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2     Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
1     pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
7     Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
2     sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
2     Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
2     sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
2     dimanche lundi mardi mercredi jeudi vendredi samedi
4     Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
2     Domingo Segunda_feira Martes Mércores Joves Venres Sábado
2     k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
2     Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
2     Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
3     ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
6     pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
7     Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
3     ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
3     vasárnap hétfö kedd szerda csütörtök péntek szombat
2     Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
2     sundio lundio mardio merkurdio jovdio venerdio saturdio
3     Minggu Senin Selasa Rabu Kamis Jumat Sabtu
2     Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
4     Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
2     domenica lunedí martedí mercoledí giovedí venerdí sabato
2     Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
1     Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
7     Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
3     sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
2     Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
3     Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12    xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
3     Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
3     Jabot Manre Juje Wonje Taije Balaire Jarere
5     geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
2     Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
2     sφndag mandag tirsdag onsdag torsdag fredag lφrdag
7     lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
4     djadomingo djaluna djamars djarason djaweps djabièrna djasabra
2     Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
3     Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
1     Domingo Lunes martes Miercoles Jueves Viernes Sabado
2     Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
2     voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
4     Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
2     nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
5     Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
2     Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
2     nedel^a pondelok utorok streda s^tvrtok piatok sobota
2     Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
2     domingo lunes martes miércoles jueves viernes sábado
2     sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
7     Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
2     söndag måndag tisdag onsdag torsdag fredag lordag
2     Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
6     Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
7     wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
5     Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
6     Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
2     nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
8     Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
6     dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
3     Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
7     iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
2     zuntik montik dinstik mitvokh donershtik fraytik shabes
7     iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
7     Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11    Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
2     Sun Moon Mars Mercury Jove Venus Saturn
2     zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2     KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
5     Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
1     Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
7     Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12    xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
4     djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
2     Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Lua

<lang lua>function split(line)

   local wa = {}
   for i in string.gmatch(line, "%S+") do
       table.insert(wa, i)
   end
   return wa

end

-- main local file = assert(io.open("days_of_week.txt", "r")) io.input(file)

local line_num = 0 while true do

   local line = io.read()
   if line == nil then break end
   line_num = line_num + 1
   if string.len(line) > 0 then
       local days = split(line)
       if #days ~= 7 then
           error("There aren't 7 days in line "..line_num)
       end
       local temp = {}
       for i,day in pairs(days) do
           if temp[day] ~= nil then
               io.stderr:write(" ∞  "..line.."\n")
           else
               temp[day] = true
           end
       end
       local length = 1
       while length < 50 do
           temp = {}
           local count = 0
           for i,day in pairs(days) do
               local key = string.sub(day, 0, length)
               if temp[key] ~= nil then break end
               temp[key] = true
               count = count + 1
           end
           if count == 7 then
               print(string.format("%2d  %s", length, line))
               break
           end
           length = length + 1
       end
   end

end</lang>

Output:
 2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4  E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
 2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2  domingu llunes martes miércoles xueves vienres sábadu
 2  Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
 6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2  Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
 2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2  nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
 2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
 1  pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
 7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2  sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
 2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2  dimanche lundi mardi mercredi jeudi vendredi samedi
 4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2  Domingo Segunda_feira Martes Mércores Joves Venres Sábado
 2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 7  pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
 7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3  vasárnap hétfö kedd szerda csütörtök péntek szombat
 2  Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
 2  sundio lundio mardio merkurdio jovdio venerdio saturdio
 3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 5  Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
 2  domenica lunedí martedí mercoledí giovedí venerdí sabato
 2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12  xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3  Jabot Manre Juje Wonje Taije Balaire Jarere
 5  geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
 2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2  sφndag mandag tirsdag onsdag torsdag fredag lφrdag
 7  lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
 4  djadomingo djaluna djamars djarason djaweps djabièrna djasabra
 2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3  Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
 1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2  Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
 2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4  Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2  domingo lunes martes miércoles jueves viernes sábado
 2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2  söndag måndag tisdag onsdag torsdag fredag lordag
 2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 7  Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
 7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6  Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
 2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 9  Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
 6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2  zuntik montik dinstik mitvokh donershtik fraytik shabes
 7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
15  Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
 2  Sun Moon Mars Mercury Jove Venus Saturn
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1  Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
 7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12  xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 4  djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
 2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Mathematica/Wolfram Language

<lang Mathematica> (*This function gives all 'heads' of str of length 1 to maxLength. Since the input data was formatted to use underscores in place of spaces, there is an edge case where distinct abbreviations derived from the input data would actually not be distinct in the 'real' abbreviations. See further comments below regarding the difference between my output and the output of other solutions.*) Abbreviations[maxLength_Integer][str_String]:=Array[StringTake[StringPadRight[str,maxLength,"_"],#]&,maxLength];

(*Given a list of words (weekday names), this function expands each to its abbreviations and then picks the first 'column' that contains no duplicates. The failure case isn't really needed for this specific data, but I included it for completeness.*) ShortestUniqueAbbreviations[list:{__String}]:=

With[
 {maxLength=Max[StringLength/@list]},
 SelectFirst[Transpose[Abbreviations[maxLength]/@list],DuplicateFreeQ,"no unique abbreviations possible"]
];

(*This function gives the minimum number of characters to distinguish the words (weekday names). It assumes data is a space separated list of weekday names (i.e. one line of the input data). I would prefer to ignore blank lines, but the spec says to return an empty string. Since all of the abbreviations should be the same length because of the padding done by Abbreviations, I could have just selected the first item rather than taking the Max of the StringLength. However, the implmenetation of Abbreviations was very specific to the format of the input data, and so using Max seemed a bit safer and more general.*) RequiredAbbreviationLength[""]=""; RequiredAbbreviationLength[input_String]:=Max[StringLength/@ShortestUniqueAbbreviations[StringSplit[input]]]; </lang>

Output:

Comment: My 16th line differs from most other solutions. Whereas the others indicate a need for 16 characters to create unique abbreviations, my solution indicates a need for 17. If you take the first 16 characters of that language's weekday names (with the underscores), you get this:

Dzeenkk-eh
Dzeehn_kk-ehreh
Dzeehn_kk-ehreh_
Tah_neesee_dzeeh
Deehn_ghee_dzee-
Tl-oowey_tts-el_
Dzeentt-ahzee

Notice that if we were to strip the underscores so that we could present the weekdays in their "true" form, the second and third names would become indistinguishable. It's not until you add the 17th character of each weekday name that the "true" abbreviations would be distinguishable. This was the only discrepancy between my solution and others. Full data follows.

2	Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2	Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4	E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2	Ehud Segno Maksegno Erob Hamus Arbe Kedame
5	Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4	Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2	domingu llunes martes miércoles xueves vienres sábadu
2	Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6	Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4	Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2	Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5	Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2	nedelia ponedelnik vtornik sriada chetvartak petak sabota
12	sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4	Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
17	Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
6	dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
2	Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
2	nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
2	nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
2	Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
2	s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
2	zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2	Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
1	pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
	
7	Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
2	sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
2	Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
2	sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
2	dimanche lundi mardi mercredi jeudi vendredi samedi
4	Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
2	Domingo Segunda_feira Martes Mércores Joves Venres Sábado
2	k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
2	Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
2	Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
3	ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
6	pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
7	Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
3	ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
3	vasárnap hétfö kedd szerda csütörtök péntek szombat
2	Sunnudagur Mánudagur ╞ri\[Delta]judagur Mi\[Delta]vikudagar Fimmtudagur FÖstudagur Laugardagur
2	sundio lundio mardio merkurdio jovdio venerdio saturdio
3	Minggu Senin Selasa Rabu Kamis Jumat Sabtu
2	Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
4	Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
2	domenica lunedí martedí mercoledí giovedí venerdí sabato
2	Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
1	Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
7	Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
3	sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
2	Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
3	Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12	xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
3	Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
3	Jabot Manre Juje Wonje Taije Balaire Jarere
5	geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
2	Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
2	s\[CurlyPhi]ndag mandag tirsdag onsdag torsdag fredag l\[CurlyPhi]rdag
7	lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
4	djadomingo djaluna djamars djarason djaweps djabièrna djasabra
2	Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
3	Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
1	Domingo Lunes martes Miercoles Jueves Viernes Sabado
2	Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
2	voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
4	Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
2	nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
5	Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
2	Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
2	nedel^a pondelok utorok streda s^tvrtok piatok sobota
2	Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
2	domingo lunes martes miércoles jueves viernes sábado
2	sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
7	Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
2	söndag måndag tisdag onsdag torsdag fredag lordag
2	Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
6	Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
7	wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
5	Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
6	Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
2	nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
8	Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
6	dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
3	Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
7	iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
2	zuntik montik dinstik mitvokh donershtik fraytik shabes
7	iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
7	Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11	Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
2	Sun Moon Mars Mercury Jove Venus Saturn
2	zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2	KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
5	Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
1	Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
7	Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12	xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
4	djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
2	Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Nim

We have chosen to ignore the case as we considerer that in line Domingo Lunes martes Miercoles Jueves Viernes Sabado, the lower case 'm' for “martes” is a mistake and should not be considered to be relevant. This is different from the choice made by most other solutions

We provide two solutions, one consisting to build the abbreviations for each language and stopping when all of them are different, the second sorting the list of day names for each language and adjusting the abbreviation length to make sure that two consecutive day names are different. The second method should be more efficient, but it doesn’t really matters here.

Using a set

<lang Nim> import sets import unicode

type Runes = seq[Rune]

var linenum = 0 for line in lines("days.txt"):

 inc linenum
 if line.len > 0:
   # Extract the day names and store them in a sorted list of sequences of runes.
   var days: seq[Runes]
   for day in line.splitWhitespace():
     days.add(day.toLower.toRunes)
   if days.len != 7:
     echo "Wrong number of days at line ", linenum
   # Build the abbreviations and store them in a set.
   var index = 0
   while true:
     var abbrevs: HashSet[seq[Rune]]
     for day in days:
       abbrevs.incl(day[0..min(index, day.high)])
     if abbrevs.card == 7:
       # All abbreviations are different: fine!
       break
     inc index
   echo index + 1, " ", line
 else:
   echo line

</lang>

Using a sorted list

<lang Nim> import algorithm import unicode

type Runes = seq[Rune]

var linenum = 0 for line in lines("days.txt"):

 inc linenum
 if line.len > 0:
   # Extract the day names and store them in a sorted list of sequences of runes.
   var days: seq[Runes]
   for day in sorted(line.toLower.splitWhitespace()):
     days.add(day.toRunes)
   if days.len != 7:
     echo "Wrong number of days at line ", linenum
   # Compare the first letters of successive day names, incrementing the upper index if necessary.
   var index = 0             # Equal to abbreviation length - 1.
   var prevday = days[0]
   for idx in 1..days.high:
     let currday = days[idx]
     if currday == prevday:
       echo "Double encountered at line ", linenum
     while currday[0..min(index, currday.high)] == prevday[0..min(index, prevday.high)]:
       inc index
     prevday = currday
   echo index + 1, " ", line
 else:
   echo line

</lang>

Output:
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2 domingu llunes martes miércoles xueves vienres sábadu
2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
2 dimanche lundi mardi mercredi jeudi vendredi samedi
4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
3 vasárnap hétfö kedd szerda csütörtök péntek szombat
2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
2 sundio lundio mardio merkurdio jovdio venerdio saturdio
3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
2 domenica lunedí martedí mercoledí giovedí venerdí sabato
2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
3 Jabot Manre Juje Wonje Taije Balaire Jarere
5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
2 Domingo Lunes martes Miercoles Jueves Viernes Sabado
2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
2 domingo lunes martes miércoles jueves viernes sábado
2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
2 söndag måndag tisdag onsdag torsdag fredag lordag
2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
2 zuntik montik dinstik mitvokh donershtik fraytik shabes
7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
2 Sun Moon Mars Mercury Jove Venus Saturn
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Objeck

Translation of: Java

<lang objeck>use System.IO.File; use Collection;

class Abbreviations {

 function : Main(args : String[]) ~ Nil {
   if(args->Size() = 1) {
     Go(args[0]);
   };
 }
 function : Go(file : String) ~ Nil {
   reader := FileReader->New(file);
   leaving {
     reader->Close();
   };
   
   cache := StringMap->New();
   line := reader->ReadString();
   while(line <> Nil) {
     if(line->Size() > 0) {
       days := line->Split(" ");
       cache->Empty();
       each(i : days) {
         day := days[i];
         cache->Insert(day, IntHolder->New(1));
       };
       if(cache->Size() < 7) {
         " ∞ {$line}"->PrintLine();
       };
       len := 1;
       while(true) {
         cache->Empty();
         each(i : days) {
           day := days[i];
           sd : String;
           if(len >= day->Size()) {
             sd := day;
           } 
           else {
             sd := day->SubString(len);
           };
           count := cache->Find(sd)->As(IntHolder);
           if(count = Nil) {
             cache->Insert(sd, IntHolder->New(1));
           }
           else {
             count->Inc();
           };
         };
         if(cache->Size() = 7) {
           "{$len} {$line}"->PrintLine();
           break;
         };
         len += 1;
       };
     };
     line := reader->ReadString();
   };
 }

}</lang>

Output:
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2 domingu llunes martes miércoles xueves vienres sábadu
2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
2 dimanche lundi mardi mercredi jeudi vendredi samedi
4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
3 vasárnap hétfö kedd szerda csütörtök péntek szombat
2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
2 sundio lundio mardio merkurdio jovdio venerdio saturdio
3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
2 domenica lunedí martedí mercoledí giovedí venerdí sabato
2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
3 Jabot Manre Juje Wonje Taije Balaire Jarere
5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
1 Domingo Lunes martes Miercoles Jueves Viernes Sabado
2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
2 domingo lunes martes miércoles jueves viernes sábado
2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
2 söndag måndag tisdag onsdag torsdag fredag lordag
2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
2 zuntik montik dinstik mitvokh donershtik fraytik shabes
7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
2 Sun Moon Mars Mercury Jove Venus Saturn
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Perl

Output is the same as for Raku.

Translation of: Raku

<lang perl>use strict; use utf8; binmode STDOUT, ":utf8";

sub auto_abbreviate {

   my($string) = @_;
   my @words = split ' ', $string;
   my $max = 0;
   return  unless @words;
   map { $max = length($_) if length($_) > $max } @words;
   for $i (1..$max) {
       my %seen;
       return $i if @words == grep {!$seen{substr($_,0,$i)}++} @words;
   }
   return '∞';

}

open $fh, '<:encoding(UTF-8)', 'DoWAKA.txt'; while ($_ = <$fh>) {

   print "$.) " . auto_abbreviate($_) . '  ' . $_;

}</lang>

Phix

The file abbrev_auto.txt was manually created from the task description. The following code assumes a more recent version of get_text() that strips any leading utf8 bom by default (0.8.0+).

constant lines = get_text("abbrev_auto.txt",GT_LF_STRIPPED)
 
for i=1 to length(lines) do
    string li = lines[i]
    if length(li) then
        sequence days = split(li,no_empty:=true)
        if length(days)!=7 then ?9/0 end if
        integer len = 1
        for j=1 to 7 do
            for k=j+1 to 7 do
                for m=1 to min(length(days[j]),length(days[k])) do
                    if days[j][m]!=days[k][m] then exit end if
                    len = max(len,m+1)
                end for
            end for
        end for
        printf(1,"%d: %s\n",{len,li})
    end if
end for
Output:
2: Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2: Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4: E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2: Ehud Segno Maksegno Erob Hamus Arbe Kedame
5: Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
...

Prolog

Works with: SWI Prolog

<lang prolog>minimum_abbreviation_length(Day_names, Min_length):- sort(Day_names, Sorted_names), minimum_abbreviation_length(Sorted_names, Min_length, 1).

minimum_abbreviation_length([_], Min_length, Min_length):- !. minimum_abbreviation_length([Name1, Name2|Rest], Min_length, M1):- common_prefix_length(Name1, Name2, Length), M2 is max(M1, Length + 1), minimum_abbreviation_length([Name2|Rest], Min_length, M2).

common_prefix_length(String1, String2, Length):- string_chars(String1, Chars1), string_chars(String2, Chars2), common_prefix_length1(Chars1, Chars2, Length, 0).

common_prefix_length1([], _, Length, Length):-!. common_prefix_length1(_, [], Length, Length):-!. common_prefix_length1([C1|_], [C2|_], Length, Length):- C1 \= C2, !. common_prefix_length1([C|Chars1], [C|Chars2], Length, L1):- L2 is L1 + 1, common_prefix_length1(Chars1, Chars2, Length, L2).

to_upper_case([], []):-!. to_upper_case([String|S], [Upper_case|U]):-

   string_upper(String, Upper_case),
   to_upper_case(S, U).

process_line(""):-

   nl,
   !.

process_line(Line):-

   split_string(Line, "\s\t", "\s\t", Day_names),
   to_upper_case(Day_names, Upper),
   minimum_abbreviation_length(Upper, Length),
   writef('%w %w\n', [Length, Line]).

process_stream(Stream):-

   read_line_to_string(Stream, String),
   String \= end_of_file,
   !,
   process_line(String),
   process_stream(Stream).

process_stream(_).

process_file(File):-

   open(File, read, Stream),
   process_stream(Stream),
   close(Stream).

main:-

   process_file("days_of_week.txt").</lang>
Output:
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2 domingu llunes martes miércoles xueves vienres sábadu
2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
2 dimanche lundi mardi mercredi jeudi vendredi samedi
4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
3 vasárnap hétfö kedd szerda csütörtök péntek szombat
2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
2 sundio lundio mardio merkurdio jovdio venerdio saturdio
3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
2 domenica lunedí martedí mercoledí giovedí venerdí sabato
2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
3 Jabot Manre Juje Wonje Taije Balaire Jarere
5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
2 Domingo Lunes martes Miercoles Jueves Viernes Sabado
2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
2 domingo lunes martes miércoles jueves viernes sábado
2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
2 söndag måndag tisdag onsdag torsdag fredag lordag
2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
2 zuntik montik dinstik mitvokh donershtik fraytik shabes
7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
2 Sun Moon Mars Mercury Jove Venus Saturn
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Python

Imperative

Works with: Python version 3.6
Translation of: Kotlin

<lang python>def shortest_abbreviation_length(line, list_size):

   words = line.split()
   word_count = len(words)
   # Can't give true answer with unexpected number of entries
   if word_count != list_size:
       raise ValueError(f'Not enough entries, expected {list_size} found {word_count}')
   # Find the small slice length that gives list_size unique values
   abbreviation_length = 1
   abbreviations = set()
   while(True):
       abbreviations = {word[:abbreviation_length] for word in words}
       if len(abbreviations) == list_size:
           return abbreviation_length
       abbreviation_length += 1
       abbreviations.clear()

def automatic_abbreviations(filename, words_per_line):

   with open(filename) as file:
       for line in file:
           line = line.rstrip()
           if len(line) > 0:
               length = shortest_abbreviation_length(line, words_per_line)
               print(f'{length:2} {line}')
           else:
               print()

automatic_abbreviations('daysOfWeek.txt', 7)</lang>

Output:
 2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
 2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2 domingu llunes martes miércoles xueves vienres sábadu
 2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
 6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
 2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
 2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
 1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

 7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
 2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2 dimanche lundi mardi mercredi jeudi vendredi samedi
 4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
 2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
 7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3 vasárnap hétfö kedd szerda csütörtök péntek szombat
 2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
 2 sundio lundio mardio merkurdio jovdio venerdio saturdio
 3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
 2 domenica lunedí martedí mercoledí giovedí venerdí sabato
 2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3 Jabot Manre Juje Wonje Taije Balaire Jarere
 5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
 2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
 7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
 4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
 2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
 1 Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
 2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2 domingo lunes martes miércoles jueves viernes sábado
 2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2 söndag måndag tisdag onsdag torsdag fredag lordag
 2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
 7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
 2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
 6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2 zuntik montik dinstik mitvokh donershtik fraytik shabes
 7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
 2 Sun Moon Mars Mercury Jove Venus Saturn
 2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
 7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
 2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Functional

In terms of generators: <lang python>import operator from itertools import (accumulate,

                      repeat)

from pathlib import Path from typing import (Iterator,

                   List,
                   Tuple)


FILEPATH = Path('days_of_week.txt')


def read_lines(path: Path) -> Iterator[str]:

   with path.open() as file:
       yield from file


def cumulative_letters(word: str) -> Iterator[str]:

   """For a word 'foo' yields 'f', 'fo', 'foo', 'foo', 'foo', ..."""
   yield from accumulate(word, operator.add)
   yield from repeat(word)


def words_cumulative_letters(words: List[str]) -> Iterator[Tuple[str, ...]]:

   """Yields cumulative letters for several words at the same time"""
   yield from zip(*map(cumulative_letters, words))


def longest_string_length(strings: Tuple[str, ...]) -> int:

   return max(map(len, strings))


def min_abbreviation_length(words: List[str]) -> int:

   def are_unique(abbreviations: Tuple[str, ...]) -> bool:
       return len(set(abbreviations)) == len(words)
   unique_abbreviations = filter(are_unique, words_cumulative_letters(words))
   return longest_string_length(next(unique_abbreviations))


def main():

   for line in read_lines(FILEPATH):
       words = line.split()
       if not words:
           print()
           continue
       count = min_abbreviation_length(words)
       print(f'{count} {line}', end=)


if __name__ == '__main__':

   main()</lang>
Output:
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2 domingu llunes martes miércoles xueves vienres sábadu
2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
2 dimanche lundi mardi mercredi jeudi vendredi samedi
4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
3 vasárnap hétfö kedd szerda csütörtök péntek szombat
2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
2 sundio lundio mardio merkurdio jovdio venerdio saturdio
3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
2 domenica lunedí martedí mercoledí giovedí venerdí sabato
2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
3 Jabot Manre Juje Wonje Taije Balaire Jarere
5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
1 Domingo Lunes martes Miercoles Jueves Viernes Sabado
2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
2 domingo lunes martes miércoles jueves viernes sábado
2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
2 söndag måndag tisdag onsdag torsdag fredag lordag
2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
2 zuntik montik dinstik mitvokh donershtik fraytik shabes
7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
2 Sun Moon Mars Mercury Jove Venus Saturn
2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau


Composition of existing generics – just one new function. (An optimisation for higher levels of code reuse, faster code development, and easier refactoring).

The generic primitives are curried, allowing for more flexible composition:

Works with: Python version 3

<lang python>Automatic abbreviations

from itertools import (accumulate, chain) from os.path import expanduser


  1. abbrevLen :: [String] -> Int

def abbrevLen(xs):

   The minimum length of prefix required to obtain
      a unique abbreviation for each string in xs.
   n = len(xs)
   return next(
       len(a[0]) for a in map(
           compose(nub)(map_(concat)),
           transpose(list(map(inits, xs)))
       ) if n == len(a)
   )


  1. TEST ----------------------------------------------------

def main():

   Test
   xs = map_(strip)(
       lines(readFile('weekDayNames.txt'))
   )
   for i, n in enumerate(map(compose(abbrevLen)(words), xs)):
       print(n, '  ', xs[i])


  1. GENERIC -------------------------------------------------
  1. compose (<<<) :: (b -> c) -> (a -> b) -> a -> c

def compose(g):

   Function composition.
   return lambda f: lambda x: g(f(x))


  1. concat :: [String] -> String

def concat(xs):

   The concatenation of a list of strings.
   return .join(xs)


  1. inits :: [a] -> a

def inits(xs):

   all initial segments of xs, shortest first.
   return list(scanl(lambda a, x: a + [x])(
       []
   )(list(xs)))


  1. lines :: String -> [String]

def lines(s):

   A list of strings,
      (containing no newline characters)
      derived from a single new-line delimited string.
   return s.splitlines()


  1. map :: (a -> b) -> [a] -> [b]

def map_(f):

   The list obtained by applying f
      to each element of xs.
   return lambda xs: list(map(f, xs))


  1. nub :: [a] -> [a]

def nub(xs):

   A list containing the same elements as xs,
      without duplicates, in the order of their
      first occurrence.
   return list(dict.fromkeys(xs))


  1. readFile :: FilePath -> IO String

def readFile(fp):

   The contents of any file at the path
      derived by expanding any ~ in fp.
   with open(expanduser(fp), 'r', encoding='utf-8') as f:
       return f.read()


  1. scanl :: (b -> a -> b) -> b -> [a] -> [b]

def scanl(f):

   scanl is like reduce, but returns a succession of
      intermediate values, building from the left.
   return lambda a: lambda xs: (
       accumulate(chain([a], xs), f)
   )


  1. strip :: String -> String

def strip(s):

   A copy of s without any leading or trailling
      white space.
   return s.strip()


  1. transpose :: Matrix a -> Matrix a

def transpose(m):

   The rows and columns of the argument transposed.
      (The matrix containers and rows can be lists or tuples).
   if m:
       inner = type(m[0])
       z = zip(*m)
       return (type(m))(
           map(inner, z) if tuple != inner else z
       )
   else:
       return m


  1. words :: String -> [String]

def words(s):

   A list of words delimited by characters
      representing white space.
   return s.split()


  1. MAIN ---

if __name__ == '__main__':

   main()</lang>
Output:
2    Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2    Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4    E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2    Ehud Segno Maksegno Erob Hamus Arbe Kedame
5    Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4    Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2    domingu llunes martes miércoles xueves vienres sábadu
2    Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6    Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4    Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2    Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5    Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2    nedelia ponedelnik vtornik sriada chetvartak petak sabota

Racket

<lang racket>#lang racket

(require racket/set)

(define (abbr-length ss)

 (for*/first ((l (in-range 1 (string-length (argmax string-length ss))))
              #:when (equal? (sequence-length
                              (for/set ((s ss))
                                (substring s 0 (min l (string-length s)))))
                             (length ss)))
   l))

(module+ main

 (define report-line
   (match-lambda
     ["" ""]
     [(and s (app string-split ss)) (format "~a ~a" (abbr-length ss) s)]))
 (for-each (compose displayln report-line) (take (file->lines "data.txt") 5)))</lang>
Output:
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit

Raku

(formerly Perl 6)

Works with: Rakudo version 2017.08

Saving the "Days of Week, Also Known As" table to a local file DoWAKA.txt. Lines that have duplicate day names will get ∞ as the minimum number of characters, as there is no amount of characters that can be entered to distinguish the days uniquely. It is somewhat unclear as to what is meant by "return a null string". I have chosen to return Nil.

Note that this is using a previous version of the date file that has erroneous duplicate day names (see line 90). Since the effort was already expended to catch such problems, it may as well be demonstrated.

<lang perl6>sub auto-abbreviate ( Str $string ) {

   return Nil unless my @words = $string.words;
   return $_ if @words».substr(0, $_).Set == @words for 1 .. @words».chars.max;
   return '∞';

}

  1. Testing
say ++$, ') ', .&auto-abbreviate, '  ', $_ for './DoWAKA.txt'.IO.lines;</lang>
Output:
1) 2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2) 2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
3) 4  E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
4) 2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
5) 5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
6) 4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
7) 2  domingu llunes martes miércoles xueves vienres sábadu
8) 2  Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
9) 6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
10) 4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
11) 2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
12) 5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
13) 2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
14) 13  sing_kei_yath sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
15) 4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16) 16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
17) 6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
18) 2  Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
19) 2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
20) 2  nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
21) 2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
22) 2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
23) 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
24) 2  Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
25) 1  pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
26) Nil  
27) 7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
28) 2  sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
29) 2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
30) 2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
31) 2  dimanche lundi mardi mercredi jeudi vendredi samedi
32) 4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
33) 2  Domingo Segunda_feira Martes Mércores Joves Venres Sábado
34) 2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
35) 2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
36) 2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
37) 3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
38) 6  pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
39) 7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
40) 3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
41) 3  vasárnap hétfö kedd szerda csütörtök péntek szombat
42) 2  Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
43) 2  sundio lundio mardio merkurdio jovdio venerdio saturdio
44) 3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
45) 2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
46) 4  Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
47) 2  domenica lunedí martedí mercoledí giovedí venerdí sabato
48) 2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
49) 1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
50) 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
51) 3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
52) 2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
53) 3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
54) 12  xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
55) 3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
56) 3  Jabot Manre Juje Wonje Taije Balaire Jarere
57) 5  geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
58) 2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
59) 2  sφndag mandag tirsdag onsdag torsdag fredag lφrdag
60) 7  lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
61) 4  djadomingo djaluna djamars djarason djaweps djabièrna djasabra
62) 2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
63) 3  Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
64) 1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
65) 2  Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
66) 2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
67) 4  Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
68) 2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
69) 5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
70) 2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
71) 2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
72) 2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
73) 2  domingo lunes martes miércoles jueves viernes sábado
74) 2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
75) 7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
76) 2  söndag måndag tisdag onsdag torsdag fredag lordag
77) 2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
78) 6  Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
79) 7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
80) 5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
81) 6  Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
82) 2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
83) 8  Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
84) 6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
85) 3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
86) 7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
87) 2  zuntik montik dinstik mitvokh donershtik fraytik shabes
88) 7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
89) 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
90) ∞  Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_gÜnÜ
91) 2  Sun Moon Mars Mercury Jove Venus Saturn
92) 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
93) 2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
94) 5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
95) 1  Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
96) 7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
97) 12  xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
98) 4  djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
99) 2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Red

<lang Red> Red []

read and convert data to a string - to char conversion is neccessary to avoid
illegal utf8 encoding error....

data: collect/into [foreach b read/binary %abbrev.txt [keep to-char b ]] ""

                                          ;; data: read %abbrev.txt - would work, if file was utf-8 encoded ...

foreach line split data newline [  ;; split data in lines at carriage return & line feed:

if  empty?  trim line [ continue ]         ;; continues at head of loop
arr: split line space                      ;; now split line in words ; accumulate in array / series

min: 1                                     ;; preset min length 
until [
                                           ;; head is the first position of series
  if head? arr [m: make map! [] ]          ;; define an empty map (key -value store)
  
  abbr: copy/part first arr min            ;; copy/part ~  leftstr of first word with length min 
  arr: either m/:abbr [                    ;; abbreviation already exists ?        
       min: min + 1
       head arr                            ;; reset series position to head 
     ][                                    ;; otherwise ....
       m/:abbr: true                       ;; mark abreviation in map as existent
       next arr                            ;; set series position to next word
     ]
 tail? arr                                 ;; this is the until condition , end /tail of  series reached ?
]
print [min line]                           ;; print automatically reduces all words in block

] </lang>

Output:
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2 domingu llunes martes miércoles xueves vienres sábadu
2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
...

REXX

<lang rexx>/*REXX program finds the minimum length abbreviation for a lists of words (from a file).*/ parse arg uw /*obtain optional arguments from the CL*/ iFID= 'ABBREV_A.TAB' /*name of the file that has the table. */ say 'minimum' /*display the first part of the title. */ say 'abbrev' center("days of the week", 80) /*display the title for the output. */ say '══════' center("", 80, '═') /*display separator for the title line.*/

                                                /* [↓]  process the file until done.   */
    do while lines(iFID)\==0; days=linein(iFID) /*read a line (should contain 7 words).*/
    minLen= abb(days)                           /*find the minimum abbreviation length.*/
    say right(minLen, 4)   '  '    days         /*display a somewhat formatted output. */
    end   /*j*/

exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ abb: procedure; parse arg x; #=words(x) /*obtain list of words; find how many.*/

    if #==0  then return                      /*check for a blank line or null line. */
    @.=                                         /*@.   is a stemmed array of the words.*/
    L=0                                         /*L    is the max length  of  "    "   */
       do j=1  for #;         @.j=word(x, j)    /*assign to array for faster processing*/
       L.j=length(@.j);       L= max(L, L.j)    /*find the maximum length of any item. */
       end   /*L*/
                                                /* [↓]  determine minimum abbrev length*/
       do m=1  for L;         $=                /*for all lengths, find a unique abbrev*/
            do k=1  to #;     a=left(@.k, m)    /*get an abbreviation (with length  M).*/
            if wordpos(a,$)\==0  then iterate M /*test this abbreviation for uniquness.*/
            $=$  a                              /*so far, it's unique; add to the list.*/
            end   /*k*/
       leave m                                  /*a good abbreviation length was found.*/
       end        /*m*/
    return m</lang>
output   when using the default input file containing the complete list of words:
minimum
abbrev                                 days of the week
══════ ════════════════════════════════════════════════════════════════════════════════
   2    Sunday Monday Tuesday Wednesday Thursday Friday Saturday
   2    Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
   4    E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
   2    Ehud Segno Maksegno Erob Hamus Arbe Kedame
   5    Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
   4    Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
   2    domingu llunes martes miércoles xueves vienres sábadu
   2    Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
   6    Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
   4    Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
   2    Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
   5    Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
   2    nedelia ponedelnik vtornik sriada chetvartak petak sabota
   4    Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
  12    sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
  16    Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
   6    dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
   2    Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
   2    nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
   2    nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
   2    Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
   2    s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
   2    zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
   2    Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
   1    pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

   7    Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
   2    sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
   2    Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
   2    sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
   2    dimanche lundi mardi mercredi jeudi vendredi samedi
   4    Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
   2    Domingo Segunda_feira Martes Mércores Joves Venres Sábado
   2    k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
   2    Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
   2    Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
   3    ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
   6    pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
   7    Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
   3    ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
   3    vasárnap hétfö kedd szerda csütörtök péntek szombat
   2    Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
   2    sundio lundio mardio merkurdio jovdio venerdio saturdio
   3    Minggu Senin Selasa Rabu Kamis Jumat Sabtu
   2    Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
   4    Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
   2    domenica lunedí martedí mercoledí giovedí venerdí sabato
   2    Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
   1    Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
   7    Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
   3    sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
   2    Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
   3    Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
  12    xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
   3    Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
   3    Jabot Manre Juje Wonje Taije Balaire Jarere
   5    geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
   2    Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
   2    sφndag mandag tirsdag onsdag torsdag fredag lφrdag
   7    lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
   4    djadomingo djaluna djamars djarason djaweps djabièrna djasabra
   2    Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
   3    Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
   1    Domingo Lunes martes Miercoles Jueves Viernes Sabado
   2    Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
   2    voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
   4    Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
   2    nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
   5    Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
   2    Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
   2    nedel^a pondelok utorok streda s^tvrtok piatok sobota
   2    Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
   2    domingo lunes martes miércoles jueves viernes sábado
   2    sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
   7    Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
   2    söndag måndag tisdag onsdag torsdag fredag lordag
   2    Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
   6    Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
   7    wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
   5    Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
   6    Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
   2    nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
   8    Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
   6    dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
   3    Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
   7    iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
   2    zuntik montik dinstik mitvokh donershtik fraytik shabes
   7    iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
   7    Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
  11    Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
   2    Sun Moon Mars Mercury Jove Venus Saturn
   2    zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
   2    KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
   5    Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
   1    Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
   7    Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
  12    xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
   4    djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
   2    Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Ruby

<lang ruby>require "abbrev"

File.read("daynames.txt").each_line do |line|

 next if line.strip.empty?
 abbr = line.split.abbrev.invert
 puts "Minimum size: #{abbr.values.max_by(&:size).size}", abbr.inspect, "\n"

end </lang>

Output:
Minimum size: 2
{"Sunday"=>"Su", "Monday"=>"M", "Tuesday"=>"Tu", "Wednesday"=>"W", "Thursday"=>"Th", "Friday"=>"F", "Saturday"=>"Sa"}

Minimum size: 2
{"Sondag"=>"So", "Maandag"=>"M", "Dinsdag"=>"Di", "Woensdag"=>"W", "Donderdag"=>"Do", "Vrydag"=>"V", "Saterdag"=>"Sa"}

Minimum size: 4
{"E_djelë"=>"E_d", "E_hënë"=>"E_h", "E_martë"=>"E_ma", "E_mërkurë"=>"E_më", "E_enjte"=>"E_e", "E_premte"=>"E_p", "E_shtunë"=>"E_s"}

Minimum size: 2
{"Ehud"=>"Eh", "Segno"=>"S", "Maksegno"=>"M", "Erob"=>"Er", "Hamus"=>"H", "Arbe"=>"A", "Kedame"=>"K"}

Minimum size: 5
{"Al_Ahad"=>"Al_Ah", "Al_Ithinin"=>"Al_I", "Al_Tholatha'a"=>"Al_T", "Al_Arbia'a"=>"Al_Ar", "Al_Kamis"=>"Al_K", "Al_Gomia'a"=>"Al_G", "Al_Sabit"=>"Al_S"}

Minimum size: 4
{"Guiragui"=>"G", "Yergou_shapti"=>"Yerg", "Yerek_shapti"=>"Yere", "Tchorek_shapti"=>"T", "Hink_shapti"=>"H", "Ourpat"=>"O", "Shapat"=>"S"}

Minimum size: 2
{"domingu"=>"d", "llunes"=>"l", "martes"=>"ma", "miércoles"=>"mi", "xueves"=>"x", "vienres"=>"v", "sábadu"=>"s"}

Minimum size: 2
{"Bazar_gÜnÜ"=>"Ba", "Birinci_gÜn"=>"Bi", "Çkinci_gÜn"=>"Ç", "ÜçÜncÜ_gÜn"=>"Ü", "DÖrdÜncÜ_gÜn"=>"D", "Bes,inci_gÜn"=>"Be", "Altòncò_gÜn"=>"A"}

Minimum size: 6
{"Igande"=>"I", "Astelehen"=>"Astel", "Astearte"=>"Astear", "Asteazken"=>"Asteaz", "Ostegun"=>"Oste", "Ostiral"=>"Osti", "Larunbat"=>"L"}

Minimum size: 4
{"Robi_bar"=>"R", "Shom_bar"=>"Shom", "Mongal_bar"=>"M", "Budhh_bar"=>"Bu", "BRihashpati_bar"=>"BR", "Shukro_bar"=>"Shu", "Shoni_bar"=>"Shon"}
(...)

Rust

<lang c>/**

* Abbreviations from tintenalarm.de
*/

use std::fs::File; use std::io; use std::io::{BufRead, BufReader};

fn main() {

   let table = read_days("weekdays.txt").expect("Error in Function read_days:");
   for line in table {
       if line.len() == 0 {
           continue;
       };
       let mut max_same = 0;
       for i in 0..(line.len() - 1) {
           for j in i + 1..line.len() {
               max_same = max_same.max(begins_with_num_same_chars(&line[i], &line[j]));
           }
       }
       println!("{}\t{:?}", max_same + 1, line);
   }

}

fn read_days(filename: &str) -> io::Result<Vec<Vec<String>>> {

   let f = File::open(filename)?;
   let reader = BufReader::new(f);
   let mut table: Vec<Vec<String>> = Vec::new();
   for line in reader.lines() {
       let mut days: Vec<String> = Vec::with_capacity(7);
       for day in line?.split_whitespace() {
           days.push(day.to_string());
       }
       table.push(days);
   }
   Ok(table)

}

fn begins_with_num_same_chars(str_a: &str, str_b: &str) -> u32 {

   let mut num = 0;
   for (pos, char_a) in str_a.chars().enumerate() {
       match str_b.chars().nth(pos) {
           Some(char_b) => {
               if char_a == char_b {
                   num = num + 1;
               } else {
                   return num;
               }
           }
           None => return num,
       }
   }
   num

}</lang>

Output:
2       ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"]
2       ["Sondag", "Maandag", "Dinsdag", "Woensdag", "Donderdag", "Vrydag", "Saterdag"]
4       ["E_djelë", "E_hënë", "E_martë", "E_mërkurë", "E_enjte", "E_premte", "E_shtunë"]
2       ["Ehud", "Segno", "Maksegno", "Erob", "Hamus", "Arbe", "Kedame"]
5       ["Al_Ahad", "Al_Ithinin", "Al_Tholatha\'a", "Al_Arbia\'a", "Al_Kamis", "Al_Gomia\'a", "Al_Sabit"]
4       ["Guiragui", "Yergou_shapti", "Yerek_shapti", "Tchorek_shapti", "Hink_shapti", "Ourpat", "Shapat"]
2       ["domingu", "llunes", "martes", "miércoles", "xueves", "vienres", "sábadu"]
2       ["Bazar_gÜnÜ", "Birinci_gÜn", "Çkinci_gÜn", "ÜçÜncÜ_gÜn", "DÖrdÜncÜ_gÜn", "Bes,inci_gÜn", "Altòncò_gÜn"]
6       ["Igande", "Astelehen", "Astearte", "Asteazken", "Ostegun", "Ostiral", "Larunbat"]
4       ["Robi_bar", "Shom_bar", "Mongal_bar", "Budhh_bar", "BRihashpati_bar", "Shukro_bar", "Shoni_bar"]
2       ["Nedjelja", "Ponedeljak", "Utorak", "Srijeda", "Cxetvrtak", "Petak", "Subota"]
5       ["Disul", "Dilun", "Dimeurzh", "Dimerc\'her", "Diriaou", "Digwener", "Disadorn"]
2       ["nedelia", "ponedelnik", "vtornik", "sriada", "chetvartak", "petak", "sabota"]
12      ["sing_kei_yaht", "sing_kei_yat", "sing_kei_yee", "sing_kei_saam", "sing_kei_sie", "sing_kei_ng", "sing_kei_luk"]
4       ["Diumenge", "Dilluns", "Dimarts", "Dimecres", "Dijous", "Divendres", "Dissabte"]
16      ["Dzeenkk-eh", "Dzeehn_kk-ehreh", "Dzeehn_kk-ehreh_nah_kay_dzeeneh", "Tah_neesee_dzeehn_neh", "Deehn_ghee_dzee-neh", "Tl-oowey_tts-el_dehlee", "Dzeentt-ahzee"]
6       ["dy_Sul", "dy_Lun", "dy_Meurth", "dy_Mergher", "dy_You", "dy_Gwener", "dy_Sadorn"]
2       ["Dimanch", "Lendi", "Madi", "Mèkredi", "Jedi", "Vandredi", "Samdi"]
2       ["nedjelja", "ponedjeljak", "utorak", "srijeda", "cxetvrtak", "petak", "subota"]
2       ["nede^le", "ponde^lí", "úterÿ", "str^eda", "c^tvrtek", "pátek", "sobota"]
2       ["Sondee", "Mondee", "Tiisiday", "Walansedee", "TOOsedee", "Feraadee", "Satadee"]
2       ["s0ndag", "mandag", "tirsdag", "onsdag", "torsdag", "fredag", "l0rdag"]
2       ["zondag", "maandag", "dinsdag", "woensdag", "donderdag", "vrijdag", "zaterdag"]
2       ["Diman^co", "Lundo", "Mardo", "Merkredo", "^Jaùdo", "Vendredo", "Sabato"]
1       ["pÜhapäev", "esmaspäev", "teisipäev", "kolmapäev", "neljapäev", "reede", "laupäev"]
7       ["Diu_prima", "Diu_sequima", "Diu_tritima", "Diu_quartima", "Diu_quintima", "Diu_sextima", "Diu_sabbata"]
2       ["sunnudagur", "mánadagur", "tÿsdaguy", "mikudagur", "hósdagur", "friggjadagur", "leygardagur"]
2       ["Yek_Sham\'beh", "Do_Sham\'beh", "Seh_Sham\'beh", "Cha\'har_Sham\'beh", "Panj_Sham\'beh", "Jom\'eh", "Sham\'beh"]
2       ["sunnuntai", "maanantai", "tiistai", "keskiviiko", "torsktai", "perjantai", "lauantai"]
2       ["dimanche", "lundi", "mardi", "mercredi", "jeudi", "vendredi", "samedi"]
4       ["Snein", "Moandei", "Tiisdei", "Woansdei", "Tonersdei", "Freed", "Sneon"]
2       ["Domingo", "Segunda_feira", "Martes", "Mércores", "Joves", "Venres", "Sábado"]
2       ["k\'vira", "orshabati", "samshabati", "otkhshabati", "khutshabati", "p\'arask\'evi", "shabati"]
2       ["Sonntag", "Montag", "Dienstag", "Mittwoch", "Donnerstag", "Freitag", "Samstag"]
2       ["Kiriaki\'", "Defte\'ra", "Tri\'ti", "Teta\'rti", "Pe\'mpti", "Paraskebi\'", "Sa\'bato"]
3       ["ravivaar", "somvaar", "mangalvaar", "budhvaar", "guruvaar", "shukravaar", "shanivaar"]
6       ["pópule", "pó`akahi", "pó`alua", "pó`akolu", "pó`ahá", "pó`alima", "pó`aono"]
7       ["Yom_rishon", "Yom_sheni", "Yom_shlishi", "Yom_revi\'i", "Yom_chamishi", "Yom_shishi", "Shabat"]
3       ["ravivara", "somavar", "mangalavar", "budhavara", "brahaspativar", "shukravara", "shanivar"]
3       ["vasárnap", "hétfö", "kedd", "szerda", "csütörtök", "péntek", "szombat"]
2       ["Sunnudagur", "Mánudagur", "╞riδjudagur", "Miδvikudagar", "Fimmtudagur", "FÖstudagur", "Laugardagur"]
2       ["sundio", "lundio", "mardio", "merkurdio", "jovdio", "venerdio", "saturdio"]
3       ["Minggu", "Senin", "Selasa", "Rabu", "Kamis", "Jumat", "Sabtu"]
2       ["Dominica", "Lunedi", "Martedi", "Mercuridi", "Jovedi", "Venerdi", "Sabbato"]
4       ["Dé_Domhnaigh", "Dé_Luain", "Dé_Máirt", "Dé_Ceadaoin", "Dé_ardaoin", "Dé_hAoine", "Dé_Sathairn"]
2       ["domenica", "lunedí", "martedí", "mercoledí", "giovedí", "venerdí", "sabato"]
2       ["Nichiyou_bi", "Getzuyou_bi", "Kayou_bi", "Suiyou_bi", "Mokuyou_bi", "Kin\'you_bi", "Doyou_bi"]
1       ["Il-yo-il", "Wol-yo-il", "Hwa-yo-il", "Su-yo-il", "Mok-yo-il", "Kum-yo-il", "To-yo-il"]
7       ["Dies_Dominica", "Dies_Lunæ", "Dies_Martis", "Dies_Mercurii", "Dies_Iovis", "Dies_Veneris", "Dies_Saturni"]
3       ["sve-tdien", "pirmdien", "otrdien", "tresvdien", "ceturtdien", "piektdien", "sestdien"]
2       ["Sekmadienis", "Pirmadienis", "Antradienis", "Trec^iadienis", "Ketvirtadienis", "Penktadienis", "S^es^tadienis"]
3       ["Wangu", "Kazooba", "Walumbe", "Mukasa", "Kiwanuka", "Nnagawonye", "Wamunyi"]
12      ["xing-_qi-_rì", "xing-_qi-_yi-.", "xing-_qi-_èr", "xing-_qi-_san-.", "xing-_qi-_sì", "xing-_qi-_wuv.", "xing-_qi-_liù"]
3       ["Jedoonee", "Jelune", "Jemayrt", "Jecrean", "Jardaim", "Jeheiney", "Jesam"]
3       ["Jabot", "Manre", "Juje", "Wonje", "Taije", "Balaire", "Jarere"]
5       ["geminrongo", "minòmishi", "mártes", "mièrkoles", "misheushi", "bèrnashi", "mishábaro"]
2       ["Ahad", "Isnin", "Selasa", "Rabu", "Khamis", "Jumaat", "Sabtu"]
2       ["sφndag", "mandag", "tirsdag", "onsdag", "torsdag", "fredag", "lφrdag"]
7       ["lo_dimenge", "lo_diluns", "lo_dimarç", "lo_dimèrcres", "lo_dijòus", "lo_divendres", "lo_dissabte"]
4       ["djadomingo", "djaluna", "djamars", "djarason", "djaweps", "djabièrna", "djasabra"]
2       ["Niedziela", "Poniedzial/ek", "Wtorek", "S,roda", "Czwartek", "Pia,tek", "Sobota"]
3       ["Domingo", "segunda-feire", "terça-feire", "quarta-feire", "quinta-feire", "sexta-feira", "såbado"]
1       ["Domingo", "Lunes", "martes", "Miercoles", "Jueves", "Viernes", "Sabado"]
2       ["Duminicª", "Luni", "Mart\'i", "Miercuri", "Joi", "Vineri", "Sâmbªtª"]
2       ["voskresenie", "ponedelnik", "vtornik", "sreda", "chetverg", "pyatnitsa", "subbota"]
4       ["Sunday", "Di-luain", "Di-màirt", "Di-ciadain", "Di-ardaoin", "Di-haoine", "Di-sathurne"]
2       ["nedjelja", "ponedjeljak", "utorak", "sreda", "cxetvrtak", "petak", "subota"]
5       ["Sontaha", "Mmantaha", "Labobedi", "Laboraro", "Labone", "Labohlano", "Moqebelo"]
2       ["Iridha-", "Sandhudha-", "Anga.haruwa-dha-", "Badha-dha-", "Brahaspa.thindha-", "Sikura-dha-", "Sena.sura-dha-"]
2       ["nedel^a", "pondelok", "utorok", "streda", "s^tvrtok", "piatok", "sobota"]
2       ["Nedelja", "Ponedeljek", "Torek", "Sreda", "Cxetrtek", "Petek", "Sobota"]
2       ["domingo", "lunes", "martes", "miércoles", "jueves", "viernes", "sábado"]
2       ["sonde", "mundey", "tude-wroko", "dride-wroko", "fode-wroko", "freyda", "Saturday"]
7       ["Jumapili", "Jumatatu", "Jumanne", "Jumatano", "Alhamisi", "Ijumaa", "Jumamosi"]
2       ["söndag", "måndag", "tisdag", "onsdag", "torsdag", "fredag", "lordag"]
2       ["Linggo", "Lunes", "Martes", "Miyerkoles", "Huwebes", "Biyernes", "Sabado"]
6       ["Lé-pài-jít", "Pài-it", "Pài-jï", "Pài-sañ", "Pài-sì", "Pài-gÖ.", "Pài-lák"]
7       ["wan-ar-tit", "wan-tjan", "wan-ang-kaan", "wan-phoet", "wan-pha-ru-hat-sa-boh-die", "wan-sook", "wan-sao"]
5       ["Tshipi", "Mosupologo", "Labobedi", "Laboraro", "Labone", "Labotlhano", "Matlhatso"]
6       ["Pazar", "Pazartesi", "Sali", "Çar,samba", "Per,sembe", "Cuma", "Cumartesi"]
2       ["nedilya", "ponedilok", "vivtorok", "sereda", "chetver", "pyatnytsya", "subota"]
8       ["Chu?_Nhâ.t", "Thú*_Hai", "Thú*_Ba", "Thú*_Tu*", "Thú*_Na\'m", "Thú*_Sáu", "Thú*_Ba?y"]
6       ["dydd_Sul", "dyds_Llun", "dydd_Mawrth", "dyds_Mercher", "dydd_Iau", "dydd_Gwener", "dyds_Sadwrn"]
3       ["Dibeer", "Altine", "Talaata", "Allarba", "Al_xebes", "Aljuma", "Gaaw"]
7       ["iCawa", "uMvulo", "uLwesibini", "uLwesithathu", "uLuwesine", "uLwesihlanu", "uMgqibelo"]
2       ["zuntik", "montik", "dinstik", "mitvokh", "donershtik", "fraytik", "shabes"]
7       ["iSonto", "uMsombuluko", "uLwesibili", "uLwesithathu", "uLwesine", "uLwesihlanu", "uMgqibelo"]
7       ["Dies_Dominica", "Dies_Lunæ", "Dies_Martis", "Dies_Mercurii", "Dies_Iovis", "Dies_Veneris", "Dies_Saturni"]
11      ["Bazar_gÜnÜ", "Bazar_ærtæsi", "Çærs,ænbæ_axs,amò", "Çærs,ænbæ_gÜnÜ", "CÜmæ_axs,amò", "CÜmæ_gÜnÜ", "CÜmæ_Senbæ"]
2       ["Sun", "Moon", "Mars", "Mercury", "Jove", "Venus", "Saturn"]
2       ["zondag", "maandag", "dinsdag", "woensdag", "donderdag", "vrijdag", "zaterdag"]
2       ["KoseEraa", "GyoOraa", "BenEraa", "Kuoraa", "YOwaaraa", "FeEraa", "Memenaa"]
5       ["Sonntag", "Montag", "Dienstag", "Mittwoch", "Donnerstag", "Freitag", "Sonnabend"]
1       ["Domingo", "Luns", "Terza_feira", "Corta_feira", "Xoves", "Venres", "Sábado"]
7       ["Dies_Solis", "Dies_Lunae", "Dies_Martis", "Dies_Mercurii", "Dies_Iovis", "Dies_Veneris", "Dies_Sabbatum"]
12      ["xing-_qi-_tiàn", "xing-_qi-_yi-.", "xing-_qi-_èr", "xing-_qi-_san-.", "xing-_qi-_sì", "xing-_qi-_wuv.", "xing-_qi-_liù"]
4       ["djadomingu", "djaluna", "djamars", "djarason", "djaweps", "djabièrnè", "djasabra"]
2       ["Killachau", "Atichau", "Quoyllurchau", "Illapachau", "Chaskachau", "Kuychichau", "Intichau"]

Scala

Functional programmed

build.sbt

<lang Scala>name  := "Abbreviations-automatic" scalaVersion := "2.13.0" version  := "0.1"

homepage  := Some(url("http://rosettacode.org/wiki/Abbreviations,_automatic#Scala"))

libraryDependencies += "com.lihaoyi" %% "os-lib" % "0.3.0"</lang>

AbbreviationsAuto.scala

<lang Scala>object AbbreviationsAuto extends App {

 private val wd = os.pwd
 def processLine(line: String): String = {
   if (line.nonEmpty) {
     val days = line.split(' ')
     val maxL = days.map(_.length).max
     val paddedNames = days.map(s => s.padTo(maxL, ' '))
     def uniqueN = (1 to maxL) // distinct filters uniques
       .map(n => paddedNames.map(_.substring(0, n)).distinct)
       .filter(_.size == paddedNames.length)  // `.distinct` filters uniques
       .head.head.length
     f"$uniqueN%3d $line" // Return by means of String Interpolation
   } else "    \"\""
 }
 os.read.lines(wd / "days_of_week.txt")
   .distinct
   .foreach(line => println(processLine(line)))

}</lang>

Output:
    ""
  2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
  2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
  4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
  2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
  5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
  4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
  2 domingu llunes martes miércoles xueves vienres sábadu
  2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
  6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
  4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
  2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
  5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
  2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
 12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
  4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
 16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
  6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
  2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
  2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
  2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
  2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
  2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
  2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
  2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
  1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
  7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
  2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
  2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
  2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
  2 dimanche lundi mardi mercredi jeudi vendredi samedi
  4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
  2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
  2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
  2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
  2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
  3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
  6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
  7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
  3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
  3 vasárnap hétfö kedd szerda csütörtök péntek szombat
  2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
  2 sundio lundio mardio merkurdio jovdio venerdio saturdio
  3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
  2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
  4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
  2 domenica lunedí martedí mercoledí giovedí venerdí sabato
  2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
  1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
  7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
  3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
  2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
  3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
 12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
  3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
  3 Jabot Manre Juje Wonje Taije Balaire Jarere
  5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
  2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
  2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
  7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
  4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
  2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
  3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
  1 Domingo Lunes martes Miercoles Jueves Viernes Sabado
  2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
  2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
  4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
  2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
  5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
  2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
  2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
  2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
  2 domingo lunes martes miércoles jueves viernes sábado
  2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
  7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
  2 söndag måndag tisdag onsdag torsdag fredag lordag
  2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
  6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
  7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
  5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
  6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
  2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
  8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
  6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
  3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
  7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
  2 zuntik montik dinstik mitvokh donershtik fraytik shabes
  7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
  2 Sun Moon Mars Mercury Jove Venus Saturn
  2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
  5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
  1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
  7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
 12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
  4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
  2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

SenseTalk

<lang sensetalk>function AbbreviationsAutomatic days put 1 into abbreviationLength put the number of items in days into len repeat forever put () into abbreviations repeat with each item day in days put the first abbreviationLength characters of day into abbreviation if abbreviations contains abbreviation exit repeat end if insert abbreviation after abbreviations if the number of items in abbreviations is len return abbreviationLength end if end repeat add 1 to abbreviationLength end repeat end AbbreviationsAutomatic</lang> <lang sensetalk>put "Weekdays.txt" into myFile

put the defaultStringEncoding into savedEncoding put "WinLatin1" into the defaultStringEncoding

open file myFile

repeat forever read from file myFile until return if it is empty then exit repeat split trim(it) by " " if the number of items in it is 0 put "" else put AbbreviationsAutomatic(it) && it end if end repeat


close file myFile

put savedEncoding into the defaultStringEncoding</lang>

Output:
2 (Sunday,Monday,Tuesday,Wednesday,Thursday,Friday,Saturday)
2 (Sondag,Maandag,Dinsdag,Woensdag,Donderdag,Vrydag,Saterdag)
4 (E_djelë,E_hënë,E_martë,E_mërkurë,E_enjte,E_premte,E_shtunë)
2 (Ehud,Segno,Maksegno,Erob,Hamus,Arbe,Kedame)
5 (Al_Ahad,Al_Ithinin,Al_Tholatha'a,Al_Arbia'a,Al_Kamis,Al_Gomia'a,Al_Sabit)
4 (Guiragui,Yergou_shapti,Yerek_shapti,Tchorek_shapti,Hink_shapti,Ourpat,Shapat)
2 (domingu,llunes,martes,miércoles,xueves,vienres,sábadu)
2 (Bazar_gÜnÜ,Birinci_gÜn,Çkinci_gÜn,ÜçÜncÜ_gÜn,DÖrdÜncÜ_gÜn,Bes,inci_gÜn,Altòncò_gÜn)
6 (Igande,Astelehen,Astearte,Asteazken,Ostegun,Ostiral,Larunbat)
4 (Robi_bar,Shom_bar,Mongal_bar,Budhh_bar,BRihashpati_bar,Shukro_bar,Shoni_bar)
[...]
2 (Killachau,Atichau,Quoyllurchau,Illapachau,Chaskachau,Kuychichau,Intichau)

Tcl

<lang tcl> set f [open abbreviations_automatic_weekdays.txt] set lines [split [read -nonewline $f] \n] close $f

foreach days $lines {

 if {[string length $days] == 0} continue
 if {[llength $days] != 7} {
   throw ERROR {not 7 days in a line}
 }
 if {[llength [lsort -unique $days]] != 7} {
   throw ERROR {not all 7 days in a line are distinct}
 }
 for {set i 0} {1} {incr i} {
   if {[llength [lsort -unique [lmap x $days {string range $x 0 $i}]]] == 7} break
 }
 incr i
 puts "$i $days"

}</lang>

Output:
2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2 domingu llunes martes miércoles xueves vienres sábadu
2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn

VBA

Function : <lang vb>Function MinimalLenght(strLine As String) As Integer Dim myVar As Variant, I As Integer, Flag As Boolean, myColl As Collection, Count As Integer

  myVar = Split(strLine, " ")
  Count = 0
  Do
     Set myColl = New Collection
     Count = Count + 1
     On Error Resume Next
     Do
        myColl.Add Left$(myVar(I), Count), Left$(myVar(I), Count)
        I = I + 1
     Loop While Err.Number = 0 And I <= UBound(myVar)
     Flag = Err.Number = 0
     On Error GoTo 0
     I = 0
     Set myColl = Nothing
  Loop While Not Flag
  MinimalLenght = Count

End Function</lang> To call it : <lang vb>Sub Main_Abbr_Auto() Dim Nb As Integer, s As String, Result() As String, c As Integer

  Nb = FreeFile
  Open "C:\Users\" & Environ("Username") & "\Desktop\Abbreviations_Auto.txt" For Input As #Nb
     While Not EOF(Nb)
        Line Input #Nb, s
        If InStr(s, "þ") > 0 Then s = Right(s, Len(s) - 2)
        If s <> vbNullString Then
           ReDim Preserve Result(c)
           Result(c) = Left$(MinimalLenght(s) & "    ", 4) & s
           Debug.Print Result(c)
           c = c + 1
        End If
     Wend
  Close #Nb

End Sub</lang>

Output:
2   Sunday Monday Tuesday Wednesday Thursday Friday Saturday
2   Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
4   E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
2   Ehud Segno Maksegno Erob Hamus Arbe Kedame
5   Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
4   Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
2   domingu llunes martes miércoles xueves vienres sábadu
2   Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
6   Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
4   Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
2   Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
5   Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
2   nedelia ponedelnik vtornik sriada chetvartak petak sabota
12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
4   Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
6   dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
2   Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
2   nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
2   nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
2   Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
2   s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
2   zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2   Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
1   pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
7   Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
2   sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
2   Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
2   sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
2   dimanche lundi mardi mercredi jeudi vendredi samedi
4   Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
2   Domingo Segunda_feira Martes Mércores Joves Venres Sábado
2   k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
2   Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
2   Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
3   ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
6   pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
7   Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
3   ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
3   vasárnap hétfö kedd szerda csütörtök péntek szombat
2   Sunnudagur Mánudagur ^%ri´�judagur Mi´�vikudagar Fimmtudagur FÖstudagur Laugardagur
2   sundio lundio mardio merkurdio jovdio venerdio saturdio
3   Minggu Senin Selasa Rabu Kamis Jumat Sabtu
2   Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
4   Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
2   domenica lunedí martedí mercoledí giovedí venerdí sabato
2   Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
1   Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
7   Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
3   sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
2   Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
3   Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12  xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
3   Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
3   Jabot Manre Juje Wonje Taije Balaire Jarere
5   geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
2   Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
2   s�ndag mandag tirsdag onsdag torsdag fredag l�rdag
7   lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
4   djadomingo djaluna djamars djarason djaweps djabièrna djasabra
2   Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
3   Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
2   Domingo Lunes martes Miercoles Jueves Viernes Sabado
2   Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
2   voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
4   Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
2   nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
5   Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
2   Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
2   nedel^a pondelok utorok streda s^tvrtok piatok sobota
2   Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
2   domingo lunes martes miércoles jueves viernes sábado
2   sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
7   Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
2   söndag måndag tisdag onsdag torsdag fredag lordag
2   Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
6   Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
7   wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
5   Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
6   Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
2   nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
8   Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
6   dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
3   Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
7   iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
2   zuntik montik dinstik mitvokh donershtik fraytik shabes
7   iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
7   Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11  Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
2   Sun Moon Mars Mercury Jove Venus Saturn
2   zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
2   KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
5   Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
1   Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
7   Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12  xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
4   djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
2   Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Visual Basic .NET

Translation of: C#

<lang vbnet>Module Module1

   Sub Main()
       Dim lines = IO.File.ReadAllLines("days_of_week.txt")
       Dim i = 0
       For Each line In lines
           i += 1
           If line.Length > 0 Then
               Dim days = line.Split()
               If days.Length <> 7 Then
                   Throw New Exception("There aren't 7 days in line " + i)
               End If
               Dim temp As New Dictionary(Of String, Integer)
               For Each d In days
                   If temp.ContainsKey(d) Then
                       Console.WriteLine(" ∞  {0}", line)
                       Continue For
                   End If
                   temp.Add(d, 1)
               Next
               Dim len = 1
               Do
                   temp.Clear()
                   For Each d In days
                       Dim key As String
                       If len < d.Length Then
                           key = d.Substring(0, len)
                       Else
                           key = d
                       End If
                       If temp.ContainsKey(key) Then
                           Exit For
                       End If
                       temp.Add(key, 1)
                   Next
                   If temp.Count = 7 Then
                       Console.WriteLine("{0,2:D}  {1}", len, line)
                       Exit Do
                   End If
                   len += 1
               Loop
           End If
       Next
   End Sub

End Module</lang>

Output:
 2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4  E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
 2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2  domingu llunes martes miércoles xueves vienres sábadu
 2  Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
 6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
12  sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2  Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
 2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2  nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
 2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
 1  pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
 7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2  sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
 2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2  dimanche lundi mardi mercredi jeudi vendredi samedi
 4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2  Domingo Segunda_feira Martes Mércores Joves Venres Sábado
 2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6  pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
 7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3  vasárnap hétfö kedd szerda csütörtök péntek szombat
 2  Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
 2  sundio lundio mardio merkurdio jovdio venerdio saturdio
 3  Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2  Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4  Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
 2  domenica lunedí martedí mercoledí giovedí venerdí sabato
 2  Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1  Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3  sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2  Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3  Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12  xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 3  Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3  Jabot Manre Juje Wonje Taije Balaire Jarere
 5  geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
 2  Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2  sφndag mandag tirsdag onsdag torsdag fredag lφrdag
 7  lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
 4  djadomingo djaluna djamars djarason djaweps djabièrna djasabra
 2  Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3  Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
 1  Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2  Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
 2  voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4  Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2  nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5  Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2  Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2  nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2  Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2  domingo lunes martes miércoles jueves viernes sábado
 2  sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7  Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2  söndag måndag tisdag onsdag torsdag fredag lordag
 2  Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6  Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
 7  wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5  Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6  Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
 2  nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8  Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
 6  dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3  Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7  iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2  zuntik montik dinstik mitvokh donershtik fraytik shabes
 7  iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7  Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11  Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
 2  Sun Moon Mars Mercury Jove Venus Saturn
 2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2  KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1  Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
 7  Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12  xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 4  djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
 2  Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Wren

Translation of: Kotlin
Library: Wren-pattern
Library: Wren-seq
Library: Wren-fmt

<lang ecmascript>import "io" for File import "/pattern" for Pattern import "/seq" for Lst import "/fmt" for Fmt

var p = Pattern.new("+1/s") var lines = File.read("days_of_week.txt").split("\n").map { |l| l.trim() } var i = 1 for (line in lines) {

   if (line == "") {
       if (i != lines.count) System.print()
   } else {
       var days = p.splitAll(line)
       if (days.count != 7) Fiber.abort("There aren't seven days in line %(i).")
       if (Lst.distinct(days).count < 7) { // implies some days have the same name
           System.print(" ∞  %(line)")
       } else {
           var len = 1
           while (true) {
               if (Lst.distinct(days.map { |d| d.take(len).join() }.toList).count == 7) {
                   Fmt.print("$2d $s", len, line)
                   break
               }
               len = len + 1
           }
       }
   }
   i = i + 1

}</lang>

Output:
 2 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 2 Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
 4 E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
 2 Ehud Segno Maksegno Erob Hamus Arbe Kedame
 5 Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
 4 Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
 2 domingu llunes martes miércoles xueves vienres sábadu
 2 Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
 6 Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
 4 Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
 2 Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
 5 Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
 2 nedelia ponedelnik vtornik sriada chetvartak petak sabota
12 sing_kei_yaht sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
 4 Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
16 Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
 6 dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
 2 Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
 2 nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
 2 nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
 2 Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
 2 s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
 2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2 Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
 1 pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev

 7 Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
 2 sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
 2 Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
 2 sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
 2 dimanche lundi mardi mercredi jeudi vendredi samedi
 4 Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
 2 Domingo Segunda_feira Martes Mércores Joves Venres Sábado
 2 k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
 2 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
 2 Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
 3 ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
 6 pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
 7 Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
 3 ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
 3 vasárnap hétfö kedd szerda csütörtök péntek szombat
 2 Sunnudagur Mánudagur ╞riδjudagur Miδvikudagar Fimmtudagur FÖstudagur Laugardagur
 2 sundio lundio mardio merkurdio jovdio venerdio saturdio
 3 Minggu Senin Selasa Rabu Kamis Jumat Sabtu
 2 Dominica Lunedi Martedi Mercuridi Jovedi Venerdi Sabbato
 4 Dé_Domhnaigh Dé_Luain Dé_Máirt Dé_Ceadaoin Dé_ardaoin Dé_hAoine Dé_Sathairn
 2 domenica lunedí martedí mercoledí giovedí venerdí sabato
 2 Nichiyou_bi Getzuyou_bi Kayou_bi Suiyou_bi Mokuyou_bi Kin'you_bi Doyou_bi
 1 Il-yo-il Wol-yo-il Hwa-yo-il Su-yo-il Mok-yo-il Kum-yo-il To-yo-il
 7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
 3 sve-tdien pirmdien otrdien tresvdien ceturtdien piektdien sestdien
 2 Sekmadienis Pirmadienis Antradienis Trec^iadienis Ketvirtadienis Penktadienis S^es^tadienis
 3 Wangu Kazooba Walumbe Mukasa Kiwanuka Nnagawonye Wamunyi
12 xing-_qi-_rì xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 3 Jedoonee Jelune Jemayrt Jecrean Jardaim Jeheiney Jesam
 3 Jabot Manre Juje Wonje Taije Balaire Jarere
 5 geminrongo minòmishi mártes mièrkoles misheushi bèrnashi mishábaro
 2 Ahad Isnin Selasa Rabu Khamis Jumaat Sabtu
 2 sφndag mandag tirsdag onsdag torsdag fredag lφrdag
 7 lo_dimenge lo_diluns lo_dimarç lo_dimèrcres lo_dijòus lo_divendres lo_dissabte
 4 djadomingo djaluna djamars djarason djaweps djabièrna djasabra
 2 Niedziela Poniedzial/ek Wtorek S,roda Czwartek Pia,tek Sobota
 3 Domingo segunda-feire terça-feire quarta-feire quinta-feire sexta-feira såbado
 1 Domingo Lunes martes Miercoles Jueves Viernes Sabado
 2 Duminicª Luni Mart'i Miercuri Joi Vineri Sâmbªtª
 2 voskresenie ponedelnik vtornik sreda chetverg pyatnitsa subbota
 4 Sunday Di-luain Di-màirt Di-ciadain Di-ardaoin Di-haoine Di-sathurne
 2 nedjelja ponedjeljak utorak sreda cxetvrtak petak subota
 5 Sontaha Mmantaha Labobedi Laboraro Labone Labohlano Moqebelo
 2 Iridha- Sandhudha- Anga.haruwa-dha- Badha-dha- Brahaspa.thindha- Sikura-dha- Sena.sura-dha-
 2 nedel^a pondelok utorok streda s^tvrtok piatok sobota
 2 Nedelja Ponedeljek Torek Sreda Cxetrtek Petek Sobota
 2 domingo lunes martes miércoles jueves viernes sábado
 2 sonde mundey tude-wroko dride-wroko fode-wroko freyda Saturday
 7 Jumapili Jumatatu Jumanne Jumatano Alhamisi Ijumaa Jumamosi
 2 söndag måndag tisdag onsdag torsdag fredag lordag
 2 Linggo Lunes Martes Miyerkoles Huwebes Biyernes Sabado
 6 Lé-pài-jít Pài-it Pài-jï Pài-sañ Pài-sì Pài-gÖ. Pài-lák
 7 wan-ar-tit wan-tjan wan-ang-kaan wan-phoet wan-pha-ru-hat-sa-boh-die wan-sook wan-sao
 5 Tshipi Mosupologo Labobedi Laboraro Labone Labotlhano Matlhatso
 6 Pazar Pazartesi Sali Çar,samba Per,sembe Cuma Cumartesi
 2 nedilya ponedilok vivtorok sereda chetver pyatnytsya subota
 8 Chu?_Nhâ.t Thú*_Hai Thú*_Ba Thú*_Tu* Thú*_Na'm Thú*_Sáu Thú*_Ba?y
 6 dydd_Sul dyds_Llun dydd_Mawrth dyds_Mercher dydd_Iau dydd_Gwener dyds_Sadwrn
 3 Dibeer Altine Talaata Allarba Al_xebes Aljuma Gaaw
 7 iCawa uMvulo uLwesibini uLwesithathu uLuwesine uLwesihlanu uMgqibelo
 2 zuntik montik dinstik mitvokh donershtik fraytik shabes
 7 iSonto uMsombuluko uLwesibili uLwesithathu uLwesine uLwesihlanu uMgqibelo
 7 Dies_Dominica Dies_Lunæ Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Saturni
11 Bazar_gÜnÜ Bazar_ærtæsi Çærs,ænbæ_axs,amò Çærs,ænbæ_gÜnÜ CÜmæ_axs,amò CÜmæ_gÜnÜ CÜmæ_Senbæ
 2 Sun Moon Mars Mercury Jove Venus Saturn
 2 zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
 2 KoseEraa GyoOraa BenEraa Kuoraa YOwaaraa FeEraa Memenaa
 5 Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Sonnabend
 1 Domingo Luns Terza_feira Corta_feira Xoves Venres Sábado
 7 Dies_Solis Dies_Lunae Dies_Martis Dies_Mercurii Dies_Iovis Dies_Veneris Dies_Sabbatum
12 xing-_qi-_tiàn xing-_qi-_yi-. xing-_qi-_èr xing-_qi-_san-. xing-_qi-_sì xing-_qi-_wuv. xing-_qi-_liù
 4 djadomingu djaluna djamars djarason djaweps djabièrnè djasabra
 2 Killachau Atichau Quoyllurchau Illapachau Chaskachau Kuychichau Intichau

Yabasic

<lang Yabasic> a = open("days_of_week.txt", "r")

while(not eof(#a))

   line input #a s$
   print buscar(s$), " ", s$

wend

close #a

sub buscar(s$)

   local n, d, i, j, s, a$, b$, r$(1)
   
   n = token(s$, r$())
   d = 1
   
   repeat
       s = true
       for i = 1 to n
           for j = i + 1 to n
               a$ = left$(r$(i), d)
               b$ = left$(r$(j), d)
               if a$ = "" or b$ = "" s = true : break 2
               if a$ = b$ s = false : d = d + 1 : break 2
           next
       next
   until(s)
   return d

end sub</lang>

zkl

zkl doesn't grok UTF-8 so I'm using a byte by byte check. It works surprisingly well. <lang zkl>nds:=File("daysOfWeek.txt").read().howza(11) // stripped lines .pump(List,Void.Filter,fcn(day){

  d,N,m := day.split(),d.len(),(0).max(d.apply("len"));  // N==7
  foreach n in ([1..m]){
     ds:=d.apply("get",0,n);  // ("Su","Mo","Tu","We","Th","Fr","Sa")
     foreach a,b in (N,[a+1..N-1]){ if(ds[a]==ds[b]) continue(3); } # Th==Fr?
     return(n,day);	// part way though the words and found unique
  }
  return(m,day); // no match nowhere

}); foreach n,s in (nds){ println("%3d %s".fmt(n,s)); }</lang>

Output:
  2  Sunday Monday Tuesday Wednesday Thursday Friday Saturday
  2  Sondag Maandag Dinsdag Woensdag Donderdag Vrydag Saterdag
  4  E_djelë E_hënë E_martë E_mërkurë E_enjte E_premte E_shtunë
  2  Ehud Segno Maksegno Erob Hamus Arbe Kedame
  5  Al_Ahad Al_Ithinin Al_Tholatha'a Al_Arbia'a Al_Kamis Al_Gomia'a Al_Sabit
  4  Guiragui Yergou_shapti Yerek_shapti Tchorek_shapti Hink_shapti Ourpat Shapat
  2  domingu llunes martes miércoles xueves vienres sábadu
  2  Bazar_gÜnÜ Birinci_gÜn Çkinci_gÜn ÜçÜncÜ_gÜn DÖrdÜncÜ_gÜn Bes,inci_gÜn Altòncò_gÜn
  6  Igande Astelehen Astearte Asteazken Ostegun Ostiral Larunbat
  4  Robi_bar Shom_bar Mongal_bar Budhh_bar BRihashpati_bar Shukro_bar Shoni_bar
  2  Nedjelja Ponedeljak Utorak Srijeda Cxetvrtak Petak Subota
  5  Disul Dilun Dimeurzh Dimerc'her Diriaou Digwener Disadorn
  2  nedelia ponedelnik vtornik sriada chetvartak petak sabota
 13  sing_kei_yath sing_kei_yat sing_kei_yee sing_kei_saam sing_kei_sie sing_kei_ng sing_kei_luk
  4  Diumenge Dilluns Dimarts Dimecres Dijous Divendres Dissabte
 16  Dzeenkk-eh Dzeehn_kk-ehreh Dzeehn_kk-ehreh_nah_kay_dzeeneh Tah_neesee_dzeehn_neh Deehn_ghee_dzee-neh Tl-oowey_tts-el_dehlee Dzeentt-ahzee
  6  dy_Sul dy_Lun dy_Meurth dy_Mergher dy_You dy_Gwener dy_Sadorn
  2  Dimanch Lendi Madi Mèkredi Jedi Vandredi Samdi
  2  nedjelja ponedjeljak utorak srijeda cxetvrtak petak subota
  2  nede^le ponde^lí úterÿ str^eda c^tvrtek pátek sobota
  2  Sondee Mondee Tiisiday Walansedee TOOsedee Feraadee Satadee
  2  s0ndag mandag tirsdag onsdag torsdag fredag l0rdag
  2  zondag maandag dinsdag woensdag donderdag vrijdag zaterdag
  2  Diman^co Lundo Mardo Merkredo ^Jaùdo Vendredo Sabato
  1  pÜhapäev esmaspäev teisipäev kolmapäev neljapäev reede laupäev
  7  Diu_prima Diu_sequima Diu_tritima Diu_quartima Diu_quintima Diu_sextima Diu_sabbata
  2  sunnudagur mánadagur tÿsdaguy mikudagur hósdagur friggjadagur leygardagur
  2  Yek_Sham'beh Do_Sham'beh Seh_Sham'beh Cha'har_Sham'beh Panj_Sham'beh Jom'eh Sham'beh
  2  sunnuntai maanantai tiistai keskiviiko torsktai perjantai lauantai
  2  dimanche lundi mardi mercredi jeudi vendredi samedi
  4  Snein Moandei Tiisdei Woansdei Tonersdei Freed Sneon
  2  Domingo Segunda_feira Martes Mércores Joves Venres Sábado
  2  k'vira orshabati samshabati otkhshabati khutshabati p'arask'evi shabati
  2  Sonntag Montag Dienstag Mittwoch Donnerstag Freitag Samstag
  2  Kiriaki' Defte'ra Tri'ti Teta'rti Pe'mpti Paraskebi' Sa'bato
  3  ravivaar somvaar mangalvaar budhvaar guruvaar shukravaar shanivaar
  7  pópule pó`akahi pó`alua pó`akolu pó`ahá pó`alima pó`aono
  7  Yom_rishon Yom_sheni Yom_shlishi Yom_revi'i Yom_chamishi Yom_shishi Shabat
  3  ravivara somavar mangalavar budhavara brahaspativar shukravara shanivar
  3  vasárnap hétfö kedd szerda csütörtök péntek szombat