Determine if a string is collapsible
From Rosetta Code
You are encouraged to solve this task according to the task description, using any language you may know.
Determine if a character string is collapsible.
And if so, collapse the string (by removing immediately repeated characters).
If a character string has immediately repeated character(s), the repeated characters are to be deleted (removed), but not the primary (1st) character(s).
An immediately repeated character is any character that is immediately followed by an
identical character (or characters). Another word choice could've been duplicated character, but that
might have ruled out (to some readers) triplicated characters ··· or more.
{This Rosetta Code task was inspired by a newly introduced (as of around November 2019) PL/I BIF: collapse.}
- Examples
In the following character string:
The better the 4-wheel drive, the further you'll be from help when ya get stuck!
Only the 2nd t, e, and l are repeated characters, indicated
by underscores (above), even though they (those characters) appear elsewhere in the character string.
So, after collapsing the string, the result would be:
The beter the 4-whel drive, the further you'l be from help when ya get stuck!
Another example:
In the following character string:
headmistressship
The "collapsed" string would be:
headmistreship
- Task
Write a subroutine/function/procedure/routine··· to locate repeated characters and collapse (delete) them from the character string. The character string can be processed from either direction.
Show all output here, on this page:
- the original string and its length
- the resultant string and its length
- the above strings should be "bracketed" with <<< and >>> (to delineate blanks)
- «««Guillemets may be used instead for "bracketing" for the more artistic programmers, shown used here»»»
Use (at least) the following five strings, all strings are length seventy-two (characters, including blanks), except the 1st string:
string
number
╔╗
1 ║╚═══════════════════════════════════════════════════════════════════════╗ ◄■■■■■■ a null string (length zero)
2 ║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║
3 ║..1111111111111111111111111111111111111111111111111111111111111117777888║
4 ║I never give 'em hell, I just tell the truth, and they think it's hell. ║
5 ║ --- Harry S Truman ║ ◄■■■■■■ has many repeated blanks
╚════════════════════════════════════════════════════════════════════════╝
Other tasks related to string operations:
- Metrics
- Counting
- Word frequency
- Letter frequency
- Jewels and stones
- I before E except after C
- Bioinformatics/base count
- Count occurrences of a substring
- Count how many vowels and consonants occur in a string
- Remove/replace
- XXXX redacted
- Remove vowels from a string
- String interpolaton (included)
- Strip block comments
- Strip comments from a string
- Strip a set of characters from a string
- Strip whitespace from a string -- top and tail
- Strip control codes and extended characters from a string
- Anagrams/Derangements/shuffling
- Word wheel
- ABC problem
- Sattolo cycle
- Knuth shuffle
- Ordered words
- Superpermutation minimisation
- Textonyms (using a phone text pad)
- Anagrams
- Anagrams/Deranged anagrams
- Permutations/Derangements
- Find/Search/Determine
- ABC words
- Odd words
- Word ladder
- Semordnilap
- Word search
- String matching
- Tea cup rim text
- Alternade words
- Changeable words
- String comparison
- Unique characters
- Unique characters in each string
- Extract file extension
- Levenshtein distance
- Palindrome detection
- Common list elements
- Longest common suffix
- Longest common prefix
- Compare a list of strings
- Longest common substring
- Find common directory path
- Words from neighbour ones
- Change e letters to i in words
- Non-continuous subsequences
- Longest common subsequence
- Longest palindromic substrings
- Longest increasing subsequence
- Words containing "the" substring
- Sum of the digits of n is substring of n
- Determine if a string is numeric
- Determine if a string is collapsible
- Determine if a string is squeezable
- Determine if a string has all unique characters
- Determine if a string has all the same characters
- Longest substrings without repeating characters
- Find words which contains all the vowels
- Find words which contains most consonants
- Find words which contains more than 3 vowels
- Find words which first and last three letters are equals
- Find words which odd letters are consonants and even letters are vowels or vice_versa
- Formatting
- Substring
- Rep-string
- Word wrap
- String case
- Align columns
- Literals/String
- Repeat a string
- Brace expansion
- Brace expansion using ranges
- Reverse a string
- Phrase reversals
- Comma quibbling
- Special characters
- String concatenation
- Substring/Top and tail
- Commatizing numbers
- Reverse words in a string
- Suffixation of decimal numbers
- Long literals, with continuations
- Numerical and alphabetical suffixes
- Abbreviations, easy
- Abbreviations, simple
- Abbreviations, automatic
- Song lyrics/poems/Mad Libs/phrases
- Mad Libs
- Magic 8-ball
- 99 Bottles of Beer
- The Name Game (a song)
- The Old lady swallowed a fly
- The Twelve Days of Christmas
- Tokenize
- Text between
- Tokenize a string
- Word break problem
- Tokenize a string with escaping
- Split a character string based on change of character
- Sequences
Contents
- 1 8080 Assembly
- 2 Ada
- 3 ALGOL 68
- 4 APL
- 5 AutoHotkey
- 6 AWK
- 7 BaCon
- 8 BASIC
- 9 BCPL
- 10 Bracmat
- 11 C
- 12 C#
- 13 C++
- 14 Clojure
- 15 Cowgol
- 16 D
- 17 Delphi
- 18 F#
- 19 Factor
- 20 FreeBASIC
- 21 Go
- 22 Groovy
- 23 Haskell
- 24 J
- 25 Java
- 26 JavaScript
- 27 jq
- 28 Julia
- 29 Kotlin
- 30 Lua
- 31 Mathematica / Wolfram Language
- 32 MATLAB / Octave
- 33 Nim
- 34 Perl
- 35 Phix
- 36 PHP
- 37 PL/M
- 38 Prolog
- 39 PureBasic
- 40 Python
- 41 Quackery
- 42 Raku
- 43 REXX
- 44 Ring
- 45 Ruby
- 46 Rust
- 47 Scala
- 48 Sidef
- 49 Smalltalk
- 50 Swift
- 51 Tcl
- 52 Visual Basic .NET
- 53 VBA
- 54 Wren
- 55 zkl
8080 Assembly[edit]
bdos: equ 5
puts: equ 9
org 100h
jmp main
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Collapse the $-terminated string at [HL]
colaps: mov b,m ; B = last character seen
inx h ; First character never collapses
mov d,h ; DE = output pointer
mov e,l
mov a,b ; Empty string?
cpi '$'
rz ; Then do nothing
cloop: mov a,m ; Get character
inx h ; Advance pointer
cmp b ; Same as last one?
jz cloop ; Then keep scanning
mov b,a ; Otherwise, it is a new one
stax d ; Store it,
inx d ; and increment output pointer.
cpi '$' ; Reached the end?
jnz cloop ; If not, next character
ret
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Code to print the output in the required format
main: lxi h,strs ; List of string pointers
loop: mov e,m ; DE = string pointer
inx h
mov d,m
inx h
mov a,e ; If zero, end
ora d
rz
push h ; Keep the list pointer
push d ; Keep the string pointer
call brstr ; Print original string in brackets
pop h ; Retrieve string pointer
push h
call colaps ; Collapse the string
pop d ; Retrieve string pointer
call brstr ; Print the collapsed string in brackets
pop h ; Retrieve the list pointer
jmp loop ; Next string
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Print string at DE in brackets with length
brstr: push d ; Store string pointer
mvi c,puts ; Print opening brackets
lxi d,open
call bdos
pop d ; Print original string
push d
mvi c,puts
call bdos
mvi c,puts ; Print closing brackets
lxi d,close
call bdos
pop h
call strlen ; Find string length
mov a,b
jmp prnum ; Print string length
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Figure out the length of a string (max 255)
strlen: mvi b,0 ; Counter
mvi a,'$' ; Terminator
sloop: cmp m ; Reached the end yet?
rz ; If so, stop
inr b ; If not, increment counter,
inx h ; and pointer,
jmp sloop ; and check next byte.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Print number in A as decimal
prnum: lxi d,num ; End of number string
prdgt: mvi b,-1 ; Quotient
ploop: inr b ; Increment quotient
sui 10 ; Subtract 10
jnc ploop ; Subtract until negative
adi '0'+10 ; Make ASCII digit
dcx d ; Store in number string
stax d
mov a,b ; If more digits,
ana a
jnz prdgt ; find next digit
mvi c,puts ; When done, print string
jmp bdos
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Formatting strings
open: db '<<<$'
close: db '>>> $'
db '***'
num: db 13,10,'$'
;;; Input strings
strs: dw str1,str2,str3,str4,str5,0
str1: db '$' ; Empty string
str2: db '"If I were two-faced, would I be wearing '
db 'this one?" --- Abraham Lincoln $'
str3: db '..111111111111111111111111111111111111111'
db '1111111111111111111111117777888$'
str4: db 'I never give ',39,'em hell, I just tell the truth, '
db 'and they think it',39,'s hell. $'
str5: db ' '
db ' --- Harry S Truman $'
- Output:
<<<>>> 0 <<<>>> 0 <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> 72 <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> 70 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> 72 <<<.178>>> 4 <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> 72 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> 69 <<< --- Harry S Truman >>> 72 <<< - Hary S Truman >>> 17
Ada[edit]
with Ada.Text_IO; use Ada.Text_IO;
procedure Test_Collapsible is
procedure Collapse (S : in String) is
Res : String (1 .. S'Length);
Len : Natural := 0;
begin
Put_Line ("Input = <<<" & S & ">>>, length =" & S'Length'Image);
for I in S'Range loop
if Len = 0 or else S(I) /= Res(Len) then
Len := Len + 1;
Res(Len) := S(I);
end if;
end loop;
Put_Line ("Output = <<<" & Res (1 .. Len) & ">>>, length =" & Len'Image);
end Collapse;
begin
Collapse ("");
Collapse ("""If I were two-faced, would I be wearing this one?"" --- Abraham Lincoln ");
Collapse ("..1111111111111111111111111111111111111111111111111111111111111117777888");
Collapse ("I never give 'em hell, I just tell the truth, and they think it's hell. ");
Collapse (" --- Harry S Truman ");
end Test_Collapsible;
- Output:
Input = <<<>>>, length = 0 Output = <<<>>>, length = 0 Input = <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>>, length = 72 Output = <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>>, length = 70 Input = <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>>, length = 72 Output = <<<.178>>>, length = 4 Input = <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>>, length = 72 Output = <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>>, length = 69 Input = <<< --- Harry S Truman >>>, length = 72 Output = <<< - Hary S Truman >>>, length = 17
ALGOL 68[edit]
BEGIN
# returns a collapsed version of s #
# i.e. s with adjacent duplicate characters removed #
PROC collapse = ( STRING s )STRING:
IF s = ""
THEN "" # empty string #
ELSE # non-empty string #
[ LWB s : UPB s ]CHAR result;
INT r pos := LWB result;
result[ r pos ] := s[ LWB s ];
FOR s pos FROM LWB s + 1 TO UPB s DO
IF result[ r pos ] /= s[ s pos ] THEN
r pos +:= 1;
result[ r pos ] := s[ s pos ]
FI
OD;
result[ LWB result : r pos ]
FI # callapse # ;
# task test cases #
[]STRING tests = ( ""
, """If I were two-faced, would I be wearing this one?"" --- Abraham Lincoln "
, "..1111111111111111111111111111111111111111111111111111111111111117777888"
, "I never give 'em hell, I just tell the truth, and they think it's hell. "
, " --- Harry S Truman "
);
FOR t pos FROM LWB tests TO UPB tests DO
STRING s = tests[ t pos ];
STRING c = collapse( s );
print( ( " <<<", s, ">>> (length ", whole( ( UPB s + 1 ) - LWB s, 0 ), ")", newline ) );
print( ( "result <<<", c, ">>> (length ", whole( ( UPB c + 1 ) - LWB c, 0 ), ")", newline ) )
OD
END
- Output:
<<<>>> (length 0)
result <<<>>> (length 0)
<<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> (length 72)
result <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> (length 70)
<<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> (length 72)
result <<<.178>>> (length 4)
<<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> (length 72)
result <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> (length 69)
<<< --- Harry S Truman >>> (length 72)
result <<< - Hary S Truman >>> (length 17)
APL[edit]
task←{
⍝ Collapse a string
collapse←{(1,¯1↓⍵≠1⌽⍵)/⍵}
⍝ Given a function ⍺⍺, display a string in brackets,
⍝ along with its length, and do the same for the result
⍝ of applying ⍺⍺ to the string.
display←{
bracket←{(⍕⍴⍵),' «««',⍵,'»»»'}
↑(⊂bracket ⍵),(⊂bracket ⍺⍺ ⍵)
}
⍝ Strings from the task
s1←''
s2←'"If I were two-faced, would I be wearing this one?"'
s2,←' --- Abraham Lincoln '
s3←'..1111111111111111111111111111111111111111111111111'
s3,←'111111111111117777888'
s4←'I never give ''em hell, I just tell the truth, '
s4,←'and they think it''s hell. '
s5←' '
s5,←' --- Harry S Truman '
strs←s1 s2 s3 s4 s5
⍝ Collapse each string and display it as specified
↑collapse display¨ strs
}
- Output:
72 «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»»
70 «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»»
72 «««..1111111111111111111111111111111111111111111111111111111111111117777888»»»
4 «««.178»»»
72 «««I never give 'em hell, I just tell the truth, and they think it's hell. »»»
69 «««I never give 'em hel, I just tel the truth, and they think it's hel. »»»
72 ««« --- Harry S Truman »»»
17 ««« - Hary S Truman »»»
AutoHotkey[edit]
collapsible_string(str){Examples:
for i, ch in StrSplit(str){
if (ch <> prev)
res .= ch
prev := ch
}
return "original string:`t" StrLen(str) " characters`t«««" str "»»»`nresultant string:`t" StrLen(res) " characters`t«««" res "»»»"
}
data := [""Outputs:
, """If I were two-faced, would I be wearing this one?"" --- Abraham Lincoln "
, "..1111111111111111111111111111111111111111111111111111111111111117777888"
, "I never give 'em hell, I just tell the truth, and they think it's hell. "
, " --- Harry S Truman "]
for i, v in data
MsgBox % := collapsible_string(v)
return
----------------------------------------- original string: 0 characters «««»»» resultant string: 0 characters «««»»» ----------------------------------------- original string: 72 characters «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» resultant string: 70 characters «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» ----------------------------------------- original string: 72 characters «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» resultant string: 4 characters «««.178»»» ----------------------------------------- original string: 72 characters «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» resultant string: 69 characters «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» ----------------------------------------- original string: 72 characters ««« --- Harry S Truman »»» resultant string: 17 characters ««« - Hary S Truman »»» -----------------------------------------
AWK[edit]
# syntax: GAWK -f DETERMINE_IF_A_STRING_IS_COLLAPSIBLE.AWK
BEGIN {
for (i=1; i<=9; i++) {
for (j=1; j<=i; j++) {
arr[0] = arr[0] i
}
}
arr[++n] = ""
arr[++n] = "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln "
arr[++n] = "..1111111111111111111111111111111111111111111111111111111111111117777888"
arr[++n] = "I never give 'em hell, I just tell the truth, and they think it's hell. "
arr[++n] = " --- Harry S Truman "
arr[++n] = "The better the 4-wheel drive, the further you'll be from help when ya get stuck!"
arr[++n] = "headmistressship"
for (i=0; i<=n; i++) {
main(arr[i])
}
exit(0)
}
function main(str, c,i,new_str,prev_c) {
for (i=1; i<=length(str); i++) {
c = substr(str,i,1)
if (prev_c != c) {
prev_c = c
new_str = new_str c
}
}
printf("old: %2d <<<%s>>>\n",length(str),str)
printf("new: %2d <<<%s>>>\n\n",length(new_str),new_str)
}
- Output:
old: 45 <<<122333444455555666666777777788888888999999999>>> new: 9 <<<123456789>>> old: 0 <<<>>> new: 0 <<<>>> old: 72 <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> new: 70 <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> old: 72 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> new: 4 <<<.178>>> old: 72 <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> new: 69 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> old: 72 <<< --- Harry S Truman >>> new: 17 <<< - Hary S Truman >>> old: 80 <<<The better the 4-wheel drive, the further you'll be from help when ya get stuck!>>> new: 77 <<<The beter the 4-whel drive, the further you'l be from help when ya get stuck!>>> old: 16 <<<headmistressship>>> new: 14 <<<headmistreship>>>
BaCon[edit]
DATA ""
DATA "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln "
DATA "..1111111111111111111111111111111111111111111111111111111111111117777888"
DATA "I never give 'em hell, I just tell the truth, and they think it's hell. "
DATA " --- Harry S Truman "
DATA "The better the 4-wheel drive, the further you'll be from help when ya get stuck!"
DATA "headmistressship"
DOTIMES 7
READ x$
found = 0
PRINT "<<<", x$, ">>> - length: ", LEN(x$)
PRINT "<<<";
FOR y = 1 TO LEN(x$)
IF MID$(x$, y, 1) <> MID$(x$, y+1, 1) THEN
PRINT MID$(x$, y, 1);
INCR found
ENDIF
NEXT
PRINT ">>> - length: ", found
DONE
- Output:
<<<>>> - length: 0 <<<>>> - length: 0 <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> - length: 72 <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> - length: 70 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> - length: 72 <<<.178>>> - length: 4 <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> - length: 72 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> - length: 69 <<< --- Harry S Truman >>> - length: 72 <<< - Hary S Truman >>> - length: 17 <<<The better the 4-wheel drive, the further you'll be from help when ya get stuck!>>> - length: 80 <<<The beter the 4-whel drive, the further you'l be from help when ya get stuck!>>> - length: 77 <<<headmistressship>>> - length: 16 <<<headmistreship>>> - length: 14
BASIC[edit]
10 READ N%
20 FOR A% = 1 TO N%
30 READ I$: GOSUB 100
40 PRINT LEN(I$); "<<<"; I$; ">>>"
50 PRINT LEN(O$); "<<<"; O$; ">>>"
55 PRINT
60 NEXT
70 END
100 REM Collapse I$ into O$
105 IF I$="" THEN O$=I$: RETURN
110 O$=SPACE$(LEN(I$))
120 P$=LEFT$(I$,1)
130 MID$(O$,1,1)=P$
140 O%=2
150 FOR I%=2 TO LEN(I$)
160 C$=MID$(I$,I%,1)
170 IF P$<>C$ THEN MID$(O$,O%,1)=C$: O%=O%+1: P$=C$
180 NEXT
190 O$=LEFT$(O$,O%-1)
200 RETURN
400 DATA 5: REM There are 5 strings
410 DATA ""
420 DATA "'If I were two-faced, would I be wearing this one?' --- Abraham Lincoln "
430 DATA "..1111111111111111111111111111111111111111111111111111111111111117777888"
440 DATA "I never give 'em hell, I just tell the truth, and they think it's hell. "
450 DATA " --- Harry S Truman "
- Output:
0 <<<>>> 0 <<<>>> 72 <<<'If I were two-faced, would I be wearing this one?' --- Abraham Lincoln>>> 70 <<<'If I were two-faced, would I be wearing this one?' - Abraham Lincoln >>> 72 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> 4 <<<.178>>> 72 <<<I never give 'em hell, I just tell the truth, and they think it's hell.>>> 69 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> 72 <<< --- Harry S Truman>>> 17 <<< - Hary S Truman >>>
BCPL[edit]
get "libhdr"
// Collapse a string
let collapse(in, out) = valof
$( let o = 0
for i = 1 to in%0
unless i>1 & in%i = in%(i-1)
$( o := o + 1
out%o := in%i
$)
out%0 := o
resultis out
$)
// Print string with brackets and length
let brackets(s) be
writef("%N: <<<%S>>>*N", s%0, s)
// Print original and collapsed version
let show(s) be
$( let v = vec 1+255/BYTESPERWORD
brackets(s)
brackets(collapse(s, v))
wrch('*N')
$)
let start() be
$( show("")
show("*"If I were two-faced, would I be wearing this one?*" --- Abraham Lincoln ")
show("..1111111111111111111111111111111111111111111111111111111111111111111788")
show("I never give 'em hell, I just tell the truth, and they think it's hell. ")
show(" --- Harry S Truman ")
$)
- Output:
0: <<<>>> 0: <<<>>> 72: <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> 70: <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> 72: <<<..1111111111111111111111111111111111111111111111111111111111111111111788>>> 4: <<<.178>>> 72: <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> 69: <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> 72: <<< --- Harry S Truman >>> 17: <<< - Hary S Truman >>>
Bracmat[edit]
( colapse
= previous
. str
$ ( vap
$ ( (
=
. !arg:!previous&
| !arg:?previous
)
. !arg
)
)
)
& ( testcolapse
= len
. ([email protected](!arg:? [?arg)&!arg)
& out$(str$(««« !arg "»»» " len$!arg))
& colapse$!arg:?arg
& out$(str$(««« !arg "»»» " len$!arg))
)
& testcolapse$
& testcolapse
$ "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln "
& testcolapse
$ "..1111111111111111111111111111111111111111111111111111111111111117777888"
& testcolapse
$ "I never give 'em hell, I just tell the truth, and they think it's hell. "
& testcolapse
$ " --- Harry S Truman "
Output
«««»»» 0 «««»»» 0 «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» 72 «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» 70 «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» 72 «««.178»»» 4 «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» 72 «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» 69 ««« --- Harry S Truman »»» 72 ««« - Hary S Truman »»» 17
C[edit]
Identical implementation as in Determine_if_a_string_is_squeezable, as both tasks are very similar. The Lincoln quote contains backslashes to accommodate the double quotes via the command line. strcmpi is not part of the C Standard Library, thus comment out the definition in the code if testing on a system where it is already included.
#include<string.h>
#include<stdlib.h>
#include<stdio.h>
#define COLLAPSE 0
#define SQUEEZE 1
typedef struct charList{
char c;
struct charList *next;
} charList;
/*
Implementing strcmpi, the case insensitive string comparator, as it is not part of the C Standard Library.
Comment this out if testing on a compiler where it is already defined.
*/
int strcmpi(char* str1,char* str2){
int len1 = strlen(str1), len2 = strlen(str2), i;
if(len1!=len2){
return 1;
}
else{
for(i=0;i<len1;i++){
if((str1[i]>='A'&&str1[i]<='Z')&&(str2[i]>='a'&&str2[i]<='z')&&(str2[i]-65!=str1[i]))
return 1;
else if((str2[i]>='A'&&str2[i]<='Z')&&(str1[i]>='a'&&str1[i]<='z')&&(str1[i]-65!=str2[i]))
return 1;
else if(str1[i]!=str2[i])
return 1;
}
}
return 0;
}
charList *strToCharList(char* str){
int len = strlen(str),i;
charList *list, *iterator, *nextChar;
list = (charList*)malloc(sizeof(charList));
list->c = str[0];
list->next = NULL;
iterator = list;
for(i=1;i<len;i++){
nextChar = (charList*)malloc(sizeof(charList));
nextChar->c = str[i];
nextChar->next = NULL;
iterator->next = nextChar;
iterator = nextChar;
}
return list;
}
char* charListToString(charList* list){
charList* iterator = list;
int count = 0,i;
char* str;
while(iterator!=NULL){
count++;
iterator = iterator->next;
}
str = (char*)malloc((count+1)*sizeof(char));
iterator = list;
for(i=0;i<count;i++){
str[i] = iterator->c;
iterator = iterator->next;
}
free(list);
str[i] = '\0';
return str;
}
char* processString(char str[100],int operation, char squeezeChar){
charList *strList = strToCharList(str),*iterator = strList, *scout;
if(operation==SQUEEZE){
while(iterator!=NULL){
if(iterator->c==squeezeChar){
scout = iterator->next;
while(scout!=NULL && scout->c==squeezeChar){
iterator->next = scout->next;
scout->next = NULL;
free(scout);
scout = iterator->next;
}
}
iterator = iterator->next;
}
}
else{
while(iterator!=NULL && iterator->next!=NULL){
if(iterator->c == (iterator->next)->c){
scout = iterator->next;
squeezeChar = iterator->c;
while(scout!=NULL && scout->c==squeezeChar){
iterator->next = scout->next;
scout->next = NULL;
free(scout);
scout = iterator->next;
}
}
iterator = iterator->next;
}
}
return charListToString(strList);
}
void printResults(char originalString[100], char finalString[100], int operation, char squeezeChar){
if(operation==SQUEEZE){
printf("Specified Operation : SQUEEZE\nTarget Character : %c",squeezeChar);
}
else
printf("Specified Operation : COLLAPSE");
printf("\nOriginal %c%c%c%s%c%c%c\nLength : %d",174,174,174,originalString,175,175,175,(int)strlen(originalString));
printf("\nFinal %c%c%c%s%c%c%c\nLength : %d\n",174,174,174,finalString,175,175,175,(int)strlen(finalString));
}
int main(int argc, char** argv){
int operation;
char squeezeChar;
if(argc<3||argc>4){
printf("Usage : %s <SQUEEZE|COLLAPSE> <String to be processed> <Character to be squeezed, if operation is SQUEEZE>\n",argv[0]);
return 0;
}
if(strcmpi(argv[1],"SQUEEZE")==0 && argc!=4){
scanf("Please enter characted to be squeezed : %c",&squeezeChar);
operation = SQUEEZE;
}
else if(argc==4){
operation = SQUEEZE;
squeezeChar = argv[3][0];
}
else if(strcmpi(argv[1],"COLLAPSE")==0){
operation = COLLAPSE;
}
if(strlen(argv[2])<2){
printResults(argv[2],argv[2],operation,squeezeChar);
}
else{
printResults(argv[2],processString(argv[2],operation,squeezeChar),operation,squeezeChar);
}
return 0;
}
Output :
C:\My Projects\networks>a collapse "The better the 4-wheel drive, the further you'll be from help when ya get stuck!" Specified Operation : COLLAPSE Original «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» Length : 80 Final «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» Length : 77 C:\My Projects\networks>a collapse headmistressship Specified Operation : COLLAPSE Original «««headmistressship»»» Length : 16 Final «««headmistreship»»» Length : 14 C:\My Projects\networks>a collapse "" Specified Operation : COLLAPSE Original «««»»» Length : 0 Final «««»»» Length : 0 C:\My Projects\networks>a collapse "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln" Specified Operation : COLLAPSE Original «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln»»» Length : 71 Final «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln»»» Length : 69 C:\My Projects\networks>a collapse ..1111111111111111111111111111111111111111111111111111111111111117777888 Specified Operation : COLLAPSE Original «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» Length : 72 Final «««.178»»» Length : 4 C:\My Projects\networks>a collapse "I never give 'em hell, I just tell the truth, and they think it's hell." Specified Operation : COLLAPSE Original «««I never give 'em hell, I just tell the truth, and they think it's hell.»»» Length : 71 Final «««I never give 'em hel, I just tel the truth, and they think it's hel.»»» Length : 68 C:\My Projects\networks>a collapse " --- Harry S Truman" Specified Operation : COLLAPSE Original ««« --- Harry S Truman»»» Length : 70 Final ««« - Hary S Truman»»» Length : 16
C#[edit]
using System;
using static System.Linq.Enumerable;
public class Program
{
static void Main()
{
string[] input = {
"",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
"\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ",
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman "
};
foreach (string s in input) {
Console.WriteLine($"old: {s.Length} «««{s}»»»");
string c = Collapse(s);
Console.WriteLine($"new: {c.Length} «««{c}»»»");
}
}
static string Collapse(string s) => string.IsNullOrEmpty(s) ? "" :
s[0] + new string(Range(1, s.Length - 1).Where(i => s[i] != s[i - 1]).Select(i => s[i]).ToArray());
}
- Output:
old: 0 «««»»» new: 0 «««»»» old: 80 «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» new: 77 «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» old: 16 «««headmistressship»»» new: 14 «««headmistreship»»» old: 72 «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» new: 70 «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» old: 72 «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» new: 4 «««.178»»» old: 72 «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» new: 69 «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» old: 72 ««« --- Harry S Truman »»» new: 17 ««« - Hary S Truman »»»
C++[edit]
The solution is a straightforward application of the standard library function "unique".
#include <string>
#include <iostream>
#include <algorithm>
template<typename char_type>
std::basic_string<char_type> collapse(std::basic_string<char_type> str) {
auto i = std::unique(str.begin(), str.end());
str.erase(i, str.end());
return str;
}
void test(const std::string& str) {
std::cout << "original string: <<<" << str << ">>>, length = " << str.length() << '\n';
std::string collapsed(collapse(str));
std::cout << "result string: <<<" << collapsed << ">>>, length = " << collapsed.length() << '\n';
std::cout << '\n';
}
int main(int argc, char** argv) {
test("");
test("\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ");
test("..1111111111111111111111111111111111111111111111111111111111111117777888");
test("I never give 'em hell, I just tell the truth, and they think it's hell. ");
test(" --- Harry S Truman ");
return 0;
}
- Output:
original string: <<<>>>, length = 0 result string: <<<>>>, length = 0 original string: <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>>, length = 72 result string: <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>>, length = 70 original string: <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>>, length = 72 result string: <<<.178>>>, length = 4 original string: <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>>, length = 72 result string: <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>>, length = 69 original string: <<< --- Harry S Truman >>>, length = 72 result string: <<< - Hary S Truman >>>, length = 17
Clojure[edit]
(defn collapse [s]
(let [runs (partition-by identity s)]
(apply str (map first runs))))
(defn run-test [s]
(let [out (collapse s)]
(str (format "Input: <<<%s>>> (len %d)\n" s (count s))
(format "becomes: <<<%s>>> (len %d)\n" out (count out)))))
- Output:
Input: <<<>>> (len 0) becomes: <<<>>> (len 0) Input: <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> (len 72) becomes: <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> (len 70) Input: <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> (len 72) becomes: <<<.178>>> (len 4) Input: <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> (len 72) becomes: <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> (len 69) Input: <<< --- Harry S Truman >>> (len 72) becomes: <<< - Hary S Truman >>> (len 17)
Cowgol[edit]
include "cowgol.coh";
include "strings.coh";
# Collapse the string at in, and store the result in the given buffer
sub collapse(in: [uint8], out: [uint8]) is
var ch := [in];
in := @next in;
loop
if ch == 0 then
[out] := 0;
return;
elseif [in] != ch then
[out] := ch;
out := @next out;
ch := [in];
end if;
in := @next in;
end loop;
end sub;
# Given a string, collapse it and print all required output
sub show(str: [uint8]) is
sub bracket_length(str: [uint8]) is
print_i32(StrLen(str) as uint32);
print(" <<<");
print(str);
print(">>>");
print_nl();
end sub;
var buf: uint8[256];
collapse(str, &buf[0]);
bracket_length(str);
bracket_length(&buf[0]);
print_nl();
end sub;
# Strings from the task
var strings: [uint8][] := {
"",
"\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ",
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman "
};
# Collapse and print each string
var i: @indexof strings := 0;
while i < @sizeof strings loop
show(strings[i]);
i := i + 1;
end loop;
- Output:
0 <<<>>> 0 <<<>>> 72 <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> 70 <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> 72 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> 4 <<<.178>>> 72 <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> 69 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> 72 <<< --- Harry S Truman >>> 17 <<< - Hary S Truman >>>
D[edit]
import std.stdio;
void collapsible(string s) {
writeln("old: <<<", s, ">>>, length = ", s.length);
write("new: <<<");
char last = '\0';
int len = 0;
foreach (c; s) {
if (c != last) {
write(c);
len++;
}
last = c;
}
writeln(">>>, length = ", len);
writeln;
}
void main() {
collapsible(``);
collapsible(`"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln `);
collapsible(`..1111111111111111111111111111111111111111111111111111111111111117777888`);
collapsible(`I never give 'em hell, I just tell the truth, and they think it's hell. `);
collapsible(` --- Harry S Truman `);
}
- Output:
old: <<<>>>, length = 0 new: <<<>>>, length = 0 old: <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>>, length = 72 new: <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>>, length = 70 old: <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>>, length = 72 new: <<<.178>>>, length = 4 old: <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>>, length = 72 new: <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>>, length = 69 old: <<< --- Harry S Truman >>>, length = 72 new: <<< - Hary S Truman >>>, length = 17
Delphi[edit]
program Determine_if_a_string_is_collapsible;
{$APPTYPE CONSOLE}
uses
System.SysUtils;
procedure collapsible(s: string);
var
c, last: char;
len: Integer;
begin
writeln('old: <<<', s, '>>>, length = ', s.length);
write('new: <<<');
last := #0;
len := 0;
for c in s do
begin
if c <> last then
begin
write(c);
inc(len);
end;
last := c;
end;
writeln('>>>, length = ', len, #10);
end;
begin
collapsible('');
collapsible('"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ');
collapsible('..1111111111111111111111111111111111111111111111111111111111111117777888');
collapsible('I never give ''em hell, I just tell the truth, and they think it''s hell. ');
collapsible(' --- Harry S Truman ');
readln;
end.
F#[edit]
// Collapse a String. Nigel Galloway: June 9th., 2020
//As per the task description a function which 'determines if a character string is collapsible' by testing if any consecutive characters are the same.
let isCollapsible n=n|>Seq.pairwise|>Seq.tryFind(fun(n,g)->n=g)
//As per the task description a function which 'if the string is collapsable, collapses the string (by removing immediately repeated characters).
let collapse n=match isCollapsible n with
Some _->let i=Seq.head n
let fN=let mutable g=i in (fun n->if n=g then false else g<-n; true)
let g=System.String([|yield i;yield! Seq.tail n|>Seq.filter fN|])
printfn "<<<%s>>> (length %d) colapses to <<<%s>>> (length %d)" n n.Length g g.Length
| _->printfn "<<<%s>>> (length %d) does not colapse" n n.Length
collapse ""
collapse "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln "
collapse "..1111111111111111111111111111111111111111111111111111111111111117777888"
collapse "I never give 'em hell, I just tell the truth, and they think it's hell. "
collapse " --- Harry S Truman "
collapse "withoutConsecutivelyRepeatedCharacters"
- Output:
<<<>>> (length 0) does not colapse <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> (length 72) collapses to <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> (length 70) <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> (length 72) collapses to <<<.178>>> (length 4) <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> (length 72) collapses to <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> (length 69) <<< --- Harry S Truman >>> (length 72) collapses to <<< - Hary S Truman >>> (length 17) <<<withoutConsecutivelyRepeatedCharacters>>> (length 38) does not collapse
Factor[edit]
USING: formatting io kernel sbufs sequences strings ;
IN: rosetta-code.string-collapse
: (collapse) ( str -- str )
unclip-slice 1string >sbuf
[ over last over = [ drop ] [ suffix! ] if ] reduce >string ;
: collapse ( str -- str ) [ "" ] [ (collapse) ] if-empty ;
: .str ( str -- ) dup length "«««%s»»» (length %d)\n" printf ;
: show-collapse ( str -- )
[ "Before collapse: " write .str ]
[ "After collapse: " write collapse .str ] bi nl ;
: collapse-demo ( -- )
{
""
"\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln "
"..1111111111111111111111111111111111111111111111111111111111111117777888"
"I never give 'em hell, I just tell the truth, and they think it's hell. "
" --- Harry S Truman "
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!"
"headmistressship"
"aardvark"
"😍😀🙌💃😍😍😍🙌"
} [ show-collapse ] each ;
MAIN: collapse-demo
- Output:
(Using some extra test cases from the Go entry.)
Before collapse: «««»»» (length 0) After collapse: «««»»» (length 0) Before collapse: «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» (length 72) After collapse: «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» (length 70) Before collapse: «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» (length 72) After collapse: «««.178»»» (length 4) Before collapse: «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» (length 72) After collapse: «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» (length 69) Before collapse: ««« --- Harry S Truman »»» (length 72) After collapse: ««« - Hary S Truman »»» (length 17) Before collapse: «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» (length 80) After collapse: «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» (length 77) Before collapse: «««headmistressship»»» (length 16) After collapse: «««headmistreship»»» (length 14) Before collapse: «««aardvark»»» (length 8) After collapse: «««ardvark»»» (length 7) Before collapse: «««😍😀🙌💃😍😍😍🙌»»» (length 8) After collapse: «««😍😀🙌💃😍🙌»»» (length 6)
FreeBASIC[edit]
Const numCad = 5
Data ""
Data "'If I were two-faced, would I be wearing this one?' --- Abraham Lincoln "
Data "..1111111111111111111111111111111111111111111111111111111111111117777888"
Data "I never give 'em hell, I just tell the truth, and they think it's hell. "
Data " --- Harry S Truman "
Dim Shared As String cadIN, cadOUT
Sub Collapse
Dim As String a, b
If cadIN = "" Then cadOUT = cadIN: Exit Sub
cadOUT = Space(Len(cadIN))
a = Left(cadIN,1)
Mid(cadOUT,1,1) = a
Dim As Integer txtOUT = 2
For i As Integer = 2 To Len(cadIN)
b = Mid(cadIN,i,1)
If a <> b Then Mid(cadOUT,txtOUT,1) = b: txtOUT += 1: a = b
Next i
cadOUT = Left(cadOUT,txtOUT-1)
End Sub
For j As Integer = 1 To numCad
Read cadIN
Collapse
Print " <<<"; cadIN; ">>> (longitud "; Len(cadIN); _
!")\n se pliega a:\n <<<"; cadOUT; ">>> (longitud "; Len(cadOUT); !")\n"
Next j
Sleep
- Output:
<<<>>> (longitud 0)
se pliega a:
<<<>>> (longitud 0)
<<<'If I were two-faced, would I be wearing this one?' --- Abraham Lincoln >>> (longitud 72)
se pliega a:
<<<'If I were two-faced, would I be wearing this one?' - Abraham Lincoln >>> (longitud 70)
<<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> (longitud 72)
se pliega a:
<<<.178>>> (longitud 4)
<<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> (longitud 72)
se pliega a:
<<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> (longitud 69)
<<< --- Harry S Truman >>> (longitud 72)
se pliega a:
<<< - Hary S Truman >>> (longitud 17)
Go[edit]
package main
import "fmt"
// Returns collapsed string, original and new lengths in
// unicode code points (not normalized).
func collapse(s string) (string, int, int) {
r := []rune(s)
le, del := len(r), 0
for i := le - 2; i >= 0; i-- {
if r[i] == r[i+1] {
copy(r[i:], r[i+1:])
del++
}
}
if del == 0 {
return s, le, le
}
r = r[:le-del]
return string(r), le, len(r)
}
func main() {
strings:= []string {
"",
`"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln `,
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
"aardvark",
"😍😀🙌💃😍😍😍🙌",
}
for _, s := range strings {
cs, olen, clen := collapse(s)
fmt.Printf("original : length = %2d, string = «««%s»»»\n", olen, s)
fmt.Printf("collapsed: length = %2d, string = «««%s»»»\n\n", clen, cs)
}
}
- Output:
original : length = 0, string = «««»»» collapsed: length = 0, string = «««»»» original : length = 72, string = «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» collapsed: length = 70, string = «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» original : length = 72, string = «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» collapsed: length = 4, string = «««.178»»» original : length = 72, string = «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» collapsed: length = 69, string = «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» original : length = 72, string = ««« --- Harry S Truman »»» collapsed: length = 17, string = ««« - Hary S Truman »»» original : length = 80, string = «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» collapsed: length = 77, string = «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» original : length = 16, string = «««headmistressship»»» collapsed: length = 14, string = «««headmistreship»»» original : length = 8, string = «««aardvark»»» collapsed: length = 7, string = «««ardvark»»» original : length = 8, string = «««😍😀🙌💃😍😍😍🙌»»» collapsed: length = 6, string = «««😍😀🙌💃😍🙌»»»
Groovy[edit]
class StringCollapsible {
static void main(String[] args) {
for ( String s : [
"",
"\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ",
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"122333444455555666666777777788888888999999999",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship"]) {
String result = collapse(s)
System.out.printf("old: %2d <<<%s>>>%nnew: %2d <<<%s>>>%n%n", s.length(), s, result.length(), result)
}
}
private static String collapse(String input) {
StringBuilder sb = new StringBuilder()
for ( int i = 0 ; i < input.length() ; i++ ) {
if ( i == 0 || input.charAt(i-1) != input.charAt(i) ) {
sb.append(input.charAt(i))
}
}
return sb.toString()
}
}
- Output:
old: 0 <<<>>> new: 0 <<<>>> old: 72 <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> new: 70 <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> old: 72 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> new: 4 <<<.178>>> old: 72 <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> new: 69 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> old: 72 <<< --- Harry S Truman >>> new: 17 <<< - Hary S Truman >>> old: 45 <<<122333444455555666666777777788888888999999999>>> new: 9 <<<123456789>>> old: 80 <<<The better the 4-wheel drive, the further you'll be from help when ya get stuck!>>> new: 77 <<<The beter the 4-whel drive, the further you'l be from help when ya get stuck!>>> old: 16 <<<headmistressship>>> new: 14 <<<headmistreship>>>
Haskell[edit]
import Text.Printf (printf)
import Data.Maybe (catMaybes)
import Control.Monad (guard)
input :: [String]
input = [ ""
, "The better the 4-wheel drive, the further you'll be from help when ya get stuck!"
, "headmistressship"
, "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln "
, "..1111111111111111111111111111111111111111111111111111111111111117777888"
, "I never give 'em hell, I just tell the truth, and they think it's hell. "
, " --- Harry S Truman "
, "😍😀🙌💃😍😍😍🙌"
]
collapse :: Eq a => [a] -> [a]
collapse = catMaybes . (\xs -> zipWith (\a b -> guard (a /= b) >> a) (Nothing : xs) (xs <> [Nothing])) . map Just
main :: IO ()
main =
mapM_ (\(a, b) -> printf "old: %3d «««%s»»»\nnew: %3d «««%s»»»\n\n" (length a) a (length b) b)
$ ((,) <*> collapse) <$> input
- Output:
old: 0 «««»»» new: 0 «««»»» old: 80 «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» new: 77 «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» old: 16 «««headmistressship»»» new: 14 «««headmistreship»»» old: 72 «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» new: 70 «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» old: 72 «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» new: 4 «««.178»»» old: 72 «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» new: 69 «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» old: 72 ««« --- Harry S Truman »»» new: 17 ««« - Hary S Truman »»» old: 8 «««😍😀🙌💃😍😍😍🙌»»» new: 6 «««😍😀🙌💃😍🙌»»»
Note that we can also directly define a predicate, and a rewrite, in terms of Data.List group,
import Data.List (group)
isCollapsible :: String -> Bool
isCollapsible = any ((1 <) . length) . group
collapsed :: String -> String
collapsed = map head . group
or, without imports, in terms of pattern matching:
isCollapsible :: String -> Bool
isCollapsible [] = False
isCollapsible [_] = False
isCollapsible (h:t@(x:_)) = h == x || isCollapsible t
collapsed :: String -> String
collapsed [] = []
collapsed [x] = [x]
collapsed (h:t@(x:_))
| h == x = collapsed t
| otherwise = h : collapsed t
J[edit]
STRINGS =: <;._2]0 :0
"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln
..1111111111111111111111111111111111111111111111111111111111111117777888
I never give 'em hell, I just tell the truth, and they think it's hell.
--- Harry S Truman
)
collapse =: (#~ (1 , 2 ~:/\ ])) ::(''"_) NB. copy dissimilar neighbors
assert 1 2 3 2 3 1 2 1 -: collapse 1 2 3 2 2 2 2 3 1 1 2 2 1 NB. test
task =: ,&(<@:(;~ (_6 + #)))&('<<<' , '>>>' ,~ ]) collapse NB. assemble the output
task&> STRINGS NB. operate on the data
+-----------------------------------------------------------------------------------+---------------------------------------------------------------------------------+
|+-+------+ |+-+------+ |
||0|<<<>>>| ||0|<<<>>>| |
|+-+------+ |+-+------+ |
+-----------------------------------------------------------------------------------+---------------------------------------------------------------------------------+
|+--+------------------------------------------------------------------------------+|+--+----------------------------------------------------------------------------+|
||72|<<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>>|||70|<<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>>||
|+--+------------------------------------------------------------------------------+|+--+----------------------------------------------------------------------------+|
+-----------------------------------------------------------------------------------+---------------------------------------------------------------------------------+
|+--+------------------------------------------------------------------------------+|+-+----------+ |
||72|<<<..1111111111111111111111111111111111111111111111111111111111111117777888>>>|||4|<<<.178>>>| |
|+--+------------------------------------------------------------------------------+|+-+----------+ |
+-----------------------------------------------------------------------------------+---------------------------------------------------------------------------------+
|+--+------------------------------------------------------------------------------+|+--+---------------------------------------------------------------------------+ |
||72|<<<I never give 'em hell, I just tell the truth, and they think it's hell. >>>|||69|<<<I never give 'em hel, I just tel the truth, and they think it's hel. >>>| |
|+--+------------------------------------------------------------------------------+|+--+---------------------------------------------------------------------------+ |
+-----------------------------------------------------------------------------------+---------------------------------------------------------------------------------+
|+--+------------------------------------------------------------------------------+|+--+-----------------------+ |
||72|<<< --- Harry S Truman >>>|||17|<<< - Hary S Truman >>>| |
|+--+------------------------------------------------------------------------------+|+--+-----------------------+ |
+-----------------------------------------------------------------------------------+---------------------------------------------------------------------------------+
Java[edit]
// Title: Determine if a string is collapsible
public class StringCollapsible {
public static void main(String[] args) {
for ( String s : new String[] {
"",
"\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ",
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"122333444455555666666777777788888888999999999",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship"}) {
String result = collapse(s);
System.out.printf("old: %2d <<<%s>>>%nnew: %2d <<<%s>>>%n%n", s.length(), s, result.length(), result);
}
}
private static String collapse(String in) {
StringBuilder sb = new StringBuilder();
for ( int i = 0 ; i < in.length() ; i++ ) {
if ( i == 0 || in.charAt(i-1) != in.charAt(i) ) {
sb.append(in.charAt(i));
}
}
return sb.toString();
}
}
- Output:
old: 0 <<<>>> new: 0 <<<>>> old: 72 <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> new: 70 <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> old: 72 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> new: 4 <<<.178>>> old: 72 <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> new: 69 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> old: 72 <<< --- Harry S Truman >>> new: 17 <<< - Hary S Truman >>> old: 45 <<<122333444455555666666777777788888888999999999>>> new: 9 <<<123456789>>> old: 80 <<<The better the 4-wheel drive, the further you'll be from help when ya get stuck!>>> new: 77 <<<The beter the 4-whel drive, the further you'l be from help when ya get stuck!>>> old: 16 <<<headmistressship>>> new: 14 <<<headmistreship>>>
JavaScript[edit]
String.prototype.collapse = function() {
let str = this;
for (let i = 0; i < str.length; i++) {
while (str[i] == str[i+1]) str = str.substr(0,i) + str.substr(i+1);
}
return str;
}
// testing
let strings = [
'',
'"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ',
'..1111111111111111111111111111111111111111111111111111111111111117777888',
`I never give 'em hell, I just tell the truth, and they think it's hell. `,
' --- Harry S Truman '
];
for (let i = 0; i < strings.length; i++) {
let str = strings[i], col = str.collapse();
console.log(`«««${str}»»» (${str.length})`);
console.log(`«««${col}»»» (${col.length})`);
}
- Output:
«««»»» (0) «««»»» (0) «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» (72) «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» (70) «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» (72) «««.178»»» (4) «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» (72) «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» (69) ««« --- Harry S Truman »»» (72) ««« - Hary S Truman »»» (17)
jq[edit]
Here we can use the Unix-like `uniq` function defined on (JSON) arrays to define `collapse` on (JSON) strings:
# Input: an array
# Output: a stream
def uniq: foreach .[] as $x ({x:nan, y:.[0]}; {x:$x, y:.x}; select(.x != .y) | .x);
def collapse: explode | [uniq] | implode;
The program for the given task can now be written in three lines:
def Guillemets: "«««\(.)»»»";
"Original: \(Guillemets) has length \(length)",
(collapse | "Collapsed \(Guillemets) has length \(length)")
Using the following invocation on the five "raw" (i.e. unquoted) strings yields the results as shown:
jq -Rrf program.jq raw.txt
Original: «««»»» has length 0
Collapsed «««»»» has length 0
Original: «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» has length 72
Collapsed «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» has length 70
Original: «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» has length 72
Collapsed «««.178»»» has length 4
Original: «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» has length 72
Collapsed «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» has length 69
Original: ««« --- Harry S Truman »»» has length 72
Collapsed ««« - Hary S Truman »»» has length 17
Julia[edit]
const teststrings = [
"",
""""If I were two-faced, would I be wearing this one?" --- Abraham Lincoln """,
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"""I never give 'em hell, I just tell the truth, and they think it's hell. """,
" --- Harry S Truman "]
function collapse(s)
len = length(s)
if len < 2
return s, len, s, len
end
result = last = s[1]
for c in s[2:end]
if c != last
last = c
result *= c
end
end
return s, len, result, length(result)
end
function testcollapse(arr)
for s in arr
(s1, len1, s2, len2) = collapse(s)
println("«««$s1»»» (length $len1)\n collapses to:\n«««$s2»»» (length $len2).\n")
end
end
testcollapse(teststrings)
- Output:
«««»»» (length 0)
collapses to:
«««»»» (length 0).
«««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» (length 72)
collapses to:
«««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» (length 70).
«««..1111111111111111111111111111111111111111111111111111111111111117777888»»» (length 72)
collapses to:
«««.178»»» (length 4).
«««I never give 'em hell, I just tell the truth, and they think it's hell. »»» (length 72)
collapses to:
«««I never give 'em hel, I just tel the truth, and they think it's hel. »»» (length 69).
««« --- Harry S Truman »»» (length 72)
collapses to:
««« - Hary S Truman »»» (length 17).
Condensed version:[edit]
const teststrings = [
"",
""""If I were two-faced, would I be wearing this one?" --- Abraham Lincoln """,
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"""I never give 'em hell, I just tell the truth, and they think it's hell. """,
" --- Harry S Truman "]
collapse(s) = (t = isempty(s) ? "" : s[1:1]; for c in s if c != t[end] t *= c end; end; t)
for s in teststrings
n, t = length(s), collapse(s)
println("«««$s»»» (length $n)\n collapses to:\n«««$t»»» (length $(length(t))).\n")
end
Kotlin[edit]
fun collapse(s: String): String {
val cs = StringBuilder()
var last: Char = 0.toChar()
for (c in s) {
if (c != last) {
cs.append(c)
last = c
}
}
return cs.toString()
}
fun main() {
val strings = arrayOf(
"",
"\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ",
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
"aardvark"
)
for (s in strings) {
val c = collapse(s)
println("original : length = ${s.length}, string = «««$s»»»")
println("collapsed : length = ${c.length}, string = «««$c»»»")
println()
}
}
- Output:
original : length = 0, string = «««»»» collapsed : length = 0, string = «««»»» original : length = 72, string = «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» collapsed : length = 70, string = «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» original : length = 72, string = «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» collapsed : length = 4, string = «««.178»»» original : length = 72, string = «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» collapsed : length = 69, string = «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» original : length = 72, string = ««« --- Harry S Truman »»» collapsed : length = 17, string = ««« - Hary S Truman »»» original : length = 80, string = «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» collapsed : length = 77, string = «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» original : length = 16, string = «««headmistressship»»» collapsed : length = 14, string = «««headmistreship»»» original : length = 8, string = «««aardvark»»» collapsed : length = 7, string = «««ardvark»»»
Lua[edit]
function collapse(s)
local ns = ""
local last = nil
for c in s:gmatch"." do
if last then
if last ~= c then
ns = ns .. c
end
last = c
else
ns = ns .. c
last = c
end
end
return ns
end
function test(s)
print("old: " .. s:len() .. " <<<" .. s .. ">>>")
local a = collapse(s)
print("new: " .. a:len() .. " <<<" .. a .. ">>>")
end
function main()
test("")
test("The better the 4-wheel drive, the further you'll be from help when ya get stuck!")
test("headmistressship")
test("\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ")
test("..1111111111111111111111111111111111111111111111111111111111111117777888")
test("I never give 'em hell, I just tell the truth, and they think it's hell. ")
test(" --- Harry S Truman ")
end
main()
- Output:
old: 0 <<<>>> new: 0 <<<>>> old: 80 <<<The better the 4-wheel drive, the further you'll be from help when ya get stuck!>>> new: 77 <<<The beter the 4-whel drive, the further you'l be from help when ya get stuck!>>> old: 16 <<<headmistressship>>> new: 14 <<<headmistreship>>> old: 72 <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> new: 70 <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> old: 72 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> new: 4 <<<.178>>> old: 72 <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> new: 69 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> old: 72 <<< --- Harry S Truman >>> new: 17 <<< - Hary S Truman >>>
Mathematica / Wolfram Language[edit]
ClearAll[StringCollapse]
StringCollapse[s_String] := FixedPoint[StringReplace[y_ ~~ y_ :> y], s]
strings = {"",
"\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ",
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman "};
Do[
Print["«««" <> s <> "»»»"];
Print["Length = ", StringLength[s]];
Print["«««" <> StringCollapse[s] <> "»»»"];
Print["Length = ", StringLength[StringCollapse[s]]]
,
{s, strings}
]
- Output:
«««»»» Length = 0 «««»»» Length = 0 «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» Length = 72 «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» Length = 70 «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» Length = 72 «««.178»»» Length = 4 «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» Length = 72 «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» Length = 69 ««« --- Harry S Truman »»» Length = 72 ««« - Hary S Truman »»» Length = 17
MATLAB / Octave[edit]
function r = collapse(s)
ix=find((s(1:end-1)==s(2:end))+1;
r=s;
r(ix)=[];
fprintf(1,'Input: <<<%s>>> length: %d\n',s,length(s));
fprintf(1,'Output: <<<%s>>> length: %d\n',r,length(r));
fprintf(1,'Character to be squeezed: "%s"\n',c);
end
collapse('', ' ')
collapse('║╚═══════════════════════════════════════════════════════════════════════╗', '-')
collapse('║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║', '7')
collapse('║..1111111111111111111111111111111111111111111111111111111111111117777888║', '.')
collapse('║I never give ''em hell, I just tell the truth, and they think it''s hell. ║', '.')
collapse('║ --- Harry S Truman ║', '.')
collapse('║ --- Harry S Truman ║', '-')
collapse('║ --- Harry S Truman ║', 'r')
- Output:
Input: <<<>>> length: 0 Output: <<<>>> length: 0 ans = Input: <<<║╚═══════════════════════════════════════════════════════════════════════╗>>> length: 222 Output: <<<║╚═══════════════════════════════════════════════════════════════════════╗>>> length: 222 ans = ║╚═══════════════════════════════════════════════════════════════════════╗ Input: <<<║"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ║>>> length: 78 Output: <<<║"If I were two-faced, would I be wearing this one?" - Abraham Lincoln ║>>> length: 76 ans = ║"If I were two-faced, would I be wearing this one?" - Abraham Lincoln ║ Input: <<<║..1111111111111111111111111111111111111111111111111111111111111117777888║>>> length: 78 Output: <<<║.178║>>> length: 10 ans = ║.178║ Input: <<<║I never give 'em hell, I just tell the truth, and they think it's hell. ║>>> length: 78 Output: <<<║I never give 'em hel, I just tel the truth, and they think it's hel. ║>>> length: 75 ans = ║I never give 'em hel, I just tel the truth, and they think it's hel. ║ Input: <<<║ --- Harry S Truman ║>>> length: 78 Output: <<<║ - Hary S Truman ║>>> length: 23 ans = ║ - Hary S Truman ║ Input: <<<║ --- Harry S Truman ║>>> length: 78 Output: <<<║ - Hary S Truman ║>>> length: 23 ans = ║ - Hary S Truman ║ Input: <<<║ --- Harry S Truman ║>>> length: 78 Output: <<<║ - Hary S Truman ║>>> length: 23 ans = ║ - Hary S Truman ║ PASSES 1 out of 1 test
Nim[edit]
import unicode, strformat
proc collapse(s: string) =
let original = s.toRunes
echo fmt"Original: length = {original.len}, string = «««{s}»»»"
var previous = Rune(0)
var collapsed: seq[Rune]
for rune in original:
if rune != previous:
collapsed.add(rune)
previous = rune
echo fmt"Collapsed: length = {collapsed.len}, string = «««{collapsed}»»»"
echo ""
const Strings = ["",
"\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ",
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
"aardvark",
"😍😀🙌💃😍😍😍🙌",]
for s in Strings:
s.collapse()
- Output:
Original: length = 0, string = «««»»» Collapsed: length = 0, string = «««»»» Original: length = 72, string = «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» Collapsed: length = 70, string = «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» Original: length = 72, string = «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» Collapsed: length = 4, string = «««.178»»» Original: length = 72, string = «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» Collapsed: length = 69, string = «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» Original: length = 72, string = ««« --- Harry S Truman »»» Collapsed: length = 17, string = ««« - Hary S Truman »»» Original: length = 80, string = «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» Collapsed: length = 77, string = «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» Original: length = 16, string = «««headmistressship»»» Collapsed: length = 14, string = «««headmistreship»»» Original: length = 8, string = «««aardvark»»» Collapsed: length = 7, string = «««ardvark»»» Original: length = 8, string = «««😍😀🙌💃😍😍😍🙌»»» Collapsed: length = 6, string = «««😍😀🙌💃😍🙌»»»
Perl[edit]
use strict;
use warnings;
use utf8;
binmode STDOUT, ":utf8";
my @lines = split "\n", <<~'STRINGS';
"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln
..1111111111111111111111111111111111111111111111111111111111111117777888
I never give 'em hell, I just tell the truth, and they think it's hell.
--- Harry S Truman
The American people have a right to know if their president is a crook.
--- Richard Nixon
AАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑ
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
STRINGS
for (@lines) {
my $squish = s/(.)\1+/$1/gr;
printf "\nLength: %2d <<<%s>>>\nCollapsible: %s\nLength: %2d <<<%s>>>\n",
length($_), $_, $_ ne $squish ? 'True' : 'False', length($squish), $squish
}
- Output:
Length: 0 <<<>>> Collapsible: False Length: 0 <<<>>> Length: 72 <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> Collapsible: True Length: 70 <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> Length: 72 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> Collapsible: True Length: 4 <<<.178>>> Length: 72 <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> Collapsible: True Length: 69 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> Length: 72 <<< --- Harry S Truman >>> Collapsible: True Length: 17 <<< - Hary S Truman >>> Length: 72 <<<The American people have a right to know if their president is a crook. >>> Collapsible: True Length: 71 <<<The American people have a right to know if their president is a crok. >>> Length: 72 <<< --- Richard Nixon >>> Collapsible: True Length: 17 <<< - Richard Nixon >>> Length: 120 <<<AАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑ>>> Collapsible: False Length: 120 <<<AАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑ>>> Length: 72 <<<AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA>>> Collapsible: True Length: 1 <<<A>>>
Phix[edit]
There is already a builtin we can abuse for this. The documentation of unique() [added for 0.8.1] states:
`If "PRESORTED" is specified, but s is not actually sorted, then only adjacent duplicates are removed.`
If you don't have builtins/punique.e to hand, you may want to take a quick look at squeeze() in
[[1]], but obviously w/o ch.
constant tests = {"",
`"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln `,
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman "},
fmt = """
length %2d input: <<<%s>>>
length %2d output: <<<%s>>>
"""
for i=1 to length(tests) do
string ti = tests[i], ci = unique(ti, "PRESORTED")
printf(1,fmt,{length(ti),ti,length(ci),ci})
end for
function collapsible(string t)
-- sequence utf32 = utf8_to_utf32(t) -- maybe
-- for i=2 to length(utf32) do -- """
-- if utf32[i]=utf32[i-1] then -- """
for i=2 to length(t) do
if t[i]=t[i-1] then
return true
end if
end for
return false
end function
puts(1,"\nAs predicate: ")
for i=1 to length(tests) do
printf(1,"%t ",collapsible(tests[i]))
end for
puts(1,"\n")
- Output:
length 0 input: <<<>>> length 0 output: <<<>>> length 72 input: <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> length 70 output: <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> length 72 input: <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> length 4 output: <<<.178>>> length 72 input: <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> length 69 output: <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> length 72 input: <<< --- Harry S Truman >>> length 17 output: <<< - Hary S Truman >>> As predicate: false true true true true
PHP[edit]
<?php
function collapseString($string) {
$previousChar = null;
$collapse = '';
$charArray = preg_split('//u', $string, -1, PREG_SPLIT_NO_EMPTY);
for ($i = 0 ; $i < count($charArray) ; $i++) {
$currentChar = $charArray[$i];
if ($previousChar !== $currentChar) {
$collapse .= $charArray[$i];
}
$previousChar = $currentChar;
}
return $collapse;
}
function isCollapsible($string) {
return ($string !== collapseString($string));
}
$strings = array(
'',
'another non colapsing string',
'"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ',
'..1111111111111111111111111111111111111111111111111111111111111117777888',
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
' --- Harry S Truman ',
'0112223333444445555556666666777777778888888889999999999',
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
'headmistressship',
"😍😀🙌💃😍😍😍🙌",
);
foreach ($strings as $original) {
echo 'Original : <<<', $original, '>>> (len=', mb_strlen($original), ')', PHP_EOL;
if (isCollapsible($original)) {
$collapse = collapseString($original);
echo 'Collapse : <<<', $collapse, '>>> (len=', mb_strlen($collapse), ')', PHP_EOL, PHP_EOL;
} else {
echo 'Collapse : string is not collapsing...', PHP_EOL, PHP_EOL;
}
}
- Output:
Original : <<<>>> (len=0) Collapse : string is not collapsing... Original : <<<another non colapsing string>>> (len=28) Collapse : string is not collapsing... Original : <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> (len=72) Collapse : <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> (len=70) Original : <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> (len=72) Collapse : <<<.178>>> (len=4) Original : <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> (len=72) Collapse : <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> (len=69) Original : <<< --- Harry S Truman >>> (len=72) Collapse : <<< - Hary S Truman >>> (len=17) Original : <<<0112223333444445555556666666777777778888888889999999999>>> (len=55) Collapse : <<<0123456789>>> (len=10) Original : <<<The better the 4-wheel drive, the further you'll be from help when ya get stuck!>>> (len=80) Collapse : <<<The beter the 4-whel drive, the further you'l be from help when ya get stuck!>>> (len=77) Original : <<<headmistressship>>> (len=16) Collapse : <<<headmistreship>>> (len=14) Original : <<<😍😀🙌💃😍😍😍🙌>>> (len=8) Collapse : <<<😍😀🙌💃😍🙌>>> (len=6)
PL/M[edit]
Because of the limited character set supported by the PL/M-80 compiler,
uppercase letters have been substituted for lowercase letters,
the question mark for the period,
and the single quotation mark for the double quotation mark.
This has no other effect on the output.
While it would be possible to write the ASCII values as numbers, this would make the code less clear.
The COLLAPSE procedure compares bytes and would be fine with any 8-bit input.
100H:
BDOS: PROCEDURE (FN, ARG); DECLARE FN BYTE, ARG ADDRESS; GO TO 5; END BDOS;
EXIT: PROCEDURE; CALL BDOS(0,0); END EXIT;
PRINT: PROCEDURE (S); DECLARE S ADDRESS; CALL BDOS(9, S); END PRINT;
/* PRINT NUMBER */
PRINT$NUMBER: PROCEDURE (N);
DECLARE S (6) BYTE INITIAL ('.....$');
DECLARE (N, P) ADDRESS, C BASED P BYTE;
P = .S(5);
DIGIT:
P = P - 1;
C = N MOD 10 + '0';
N = N / 10;
IF N > 0 THEN GO TO DIGIT;
CALL PRINT(P);
END PRINT$NUMBER;
/* STRING LENGTH */
STR$LEN: PROCEDURE (STR) ADDRESS;
DECLARE (STR, I) ADDRESS, S BASED STR BYTE;
I = 0;
DO WHILE S(I) <> '$';
I = I + 1;
END;
RETURN I;
END STR$LEN;
/* COLLAPSE */
COLLAPSE: PROCEDURE (IN, OUT);
DECLARE (IN, OUT) ADDRESS, (I BASED IN, O BASED OUT, C) BYTE;
C = I;
DO WHILE C <> '$';
IN = IN + 1;
IF I <> C THEN DO;
O = C;
OUT = OUT + 1;
C = I;
END;
END;
O = '$';
END COLLAPSE;
/* PRINT STRING AND LENGTH WITH BRACKETS */
PRINT$BRACKETS: PROCEDURE (S);
DECLARE S ADDRESS;
CALL PRINT$NUMBER(STR$LEN(S));
CALL PRINT(.' <<<$');
CALL PRINT(S);
CALL PRINT(.('>>>',13,10,'$'));
END PRINT$BRACKETS;
/* GIVEN A STRING, PRINT IT AND ITS COLLAPSED FORM */
SHOW: PROCEDURE (S);
DECLARE S ADDRESS, BUFFER (256) BYTE;
CALL COLLAPSE(S, .BUFFER);
CALL PRINT$BRACKETS(S);
CALL PRINT$BRACKETS(.BUFFER);
CALL PRINT(.(13,10,'$'));
END SHOW;
/* STRINGS FROM THE TASK */
DECLARE X (5) ADDRESS;
X(0)=.'$';
X(1)=.('''IF I WERE TWO-FACED, WOULD I BE WEARING ',
'THIS ONE.'' --- ABRAHAM LINCOLN $');
X(2)=.('..111111111111111111111111111111111111111',
'1111111111111111111111117777888$');
X(3)=.('I NEVER GIVE ''EM HELL, I JUST TELL THE TR',
'UTH, AND THEY THINK IT''S HELL. $');
X(4)=.(' ',
' --- HARRY S TRUMAN $');
DECLARE I BYTE;
DO I=0 TO LAST(X);
CALL SHOW(X(I));
END;
CALL EXIT;
EOF
- Output:
0 <<<>>> 0 <<<>>> 72 <<<'IF I WERE TWO-FACED, WOULD I BE WEARING THIS ONE.' --- ABRAHAM LINCOLN >>> 70 <<<'IF I WERE TWO-FACED, WOULD I BE WEARING THIS ONE.' - ABRAHAM LINCOLN >>> 72 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> 4 <<<.178>>> 72 <<<I NEVER GIVE 'EM HELL, I JUST TELL THE TRUTH, AND THEY THINK IT'S HELL. >>> 69 <<<I NEVER GIVE 'EM HEL, I JUST TEL THE TRUTH, AND THEY THINK IT'S HEL. >>> 72 <<< --- HARRY S TRUMAN >>> 17 <<< - HARY S TRUMAN >>>
Prolog[edit]
collapse_( [], [] ).
collapse_( [A], [A] ).
collapse_( [A,A|T], R ) :- collapse_( [A|T], R ).
collapse_( [A,B|T], [A|R] ) :- dif( A, B ), collapse_( [B|T], R ).
collapse( Str, Collapsed ) :-
string_chars( Str, Chars ),
collapse_( Chars, Result ),
string_chars( Collapsed, Result ).
- Output:
?- collapse("122333444455555666666777777788888888999999999", New).
New = "123456789" .
?- collapse("", New).
New = "" .
?- collapse("\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ", New).
New = "\"If I were two-faced, would I be wearing this one?\" - Abraham Lincoln " .
?- collapse("..1111111111111111111111111111111111111111111111111111111111111117777888", New).
New = ".178" .
?- collapse("I never give 'em hell, I just tell the truth, and they think it's hell. ", New).
New = "I never give 'em hel, I just tel the truth, and they think it's hel. " .
?- collapse(" --- Harry S Truman ", New).
New = " - Hary S Truman " .
?- collapse("The better the 4-wheel drive, the further you'll be from help when ya get stuck!", New).
New = "The beter the 4-whel drive, the further you'l be from help when ya get stuck!" .
33 ?- collapse("headmistressship", New).
New = "headmistreship" .
To determine if a string is collapsed or not, query if the result string is the same as the starting string. eg:
35 ?- S = "122333444455555666666777777788888888999999999", collapse(S,S). false. 37 ?- S = "123456789", collapse(S,S). S = "123456789" .
PureBasic[edit]
EnableExplicit
DataSection
STR1:
Data.s ""
STR2:
Data.s "'If I were two-faced, would I be wearing this one?' --- Abraham Lincoln "
STR3:
Data.s "..1111111111111111111111111111111111111111111111111111111111111117777888"
STR4:
Data.s "I never give 'em hell, I just tell the truth, and they think it's hell. "
STR5:
Data.s " --- Harry S Truman "
EndDataSection
Procedure.s collapse(txt$)
Define *c.Character=@txt$, last.c=0, result$
While *c\c
If *c\c<>last
result$+Chr(*c\c)
last=*c\c
EndIf
*c+SizeOf(Character)
Wend
ProcedureReturn result$
EndProcedure
OpenConsole("")
Define *p_data=?STR1, buf$
While *p_data<=?STR4+StringByteLength(PeekS(?STR4))+2
buf$=PeekS(*p_data)
PrintN("Before collapse: «««"+buf$+"»»» (length: "+Str(Len(buf$))+")")
buf$=collapse(PeekS(*p_data))
PrintN("After collapse: «««"+buf$+~"»»» (length: "+Str(Len(buf$))+~")\n")
*p_data+StringByteLength(PeekS(*p_data))+2
Wend
Input()
- Output:
Before collapse: «««»»» (length: 0) After collapse: «««»»» (length: 0) Before collapse: «««'If I were two-faced, would I be wearing this one?' --- Abraham Lincoln »»» (length: 72) After collapse: «««'If I were two-faced, would I be wearing this one?' - Abraham Lincoln »»» (length: 70) Before collapse: «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» (length: 72) After collapse: «««.178»»» (length: 4) Before collapse: «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» (length: 72) After collapse: «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» (length: 69) Before collapse: ««« --- Harry S Truman »»» (length: 72) After collapse: ««« - Hary S Truman »»» (length: 17)
Python[edit]
from itertools import groupby
def collapser(txt):
return ''.join(item for item, grp in groupby(txt))
if __name__ == '__main__':
strings = [
"",
'"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ',
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
"aardvark",
"😍😀🙌💃😍😍😍🙌",
]
for txt in strings:
this = "Original"
print(f"\n{this:14} Size: {len(txt)} «««{txt}»»»" )
this = "Collapsed"
sqz = collapser(txt)
print(f"{this:>14} Size: {len(sqz)} «««{sqz}»»»" )
- Output:
Original Size: 0 «««»»»
Collapsed Size: 0 «««»»»
Original Size: 72 «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»»
Collapsed Size: 70 «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»»
Original Size: 72 «««..1111111111111111111111111111111111111111111111111111111111111117777888»»»
Collapsed Size: 4 «««.178»»»
Original Size: 72 «««I never give 'em hell, I just tell the truth, and they think it's hell. »»»
Collapsed Size: 69 «««I never give 'em hel, I just tel the truth, and they think it's hel. »»»
Original Size: 72 ««« --- Harry S Truman »»»
Collapsed Size: 17 ««« - Hary S Truman »»»
Original Size: 80 «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»»
Collapsed Size: 77 «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»»
Original Size: 16 «««headmistressship»»»
Collapsed Size: 14 «««headmistreship»»»
Original Size: 8 «««aardvark»»»
Collapsed Size: 7 «««ardvark»»»
Original Size: 8 «««😍😀🙌💃😍😍😍🙌»»»
Collapsed Size: 6 «««😍😀🙌💃😍🙌»»»
and for the missing predicate, foregrounded in the task title, and already forgotten in the listing of tests:
'''Determining if a string is collapsible'''
from operator import eq
# isCollapsible :: String -> Bool
def isCollapsible(s):
'''True if s contains any consecutively
repeated characters.
'''
return False if 2 > len(s) else (
any(map(eq, s, s[1:]))
)
# ------------------------- TEST --------------------------
# main :: IO ()
def main():
'''Determining whether each string is collapsible'''
xs = [
"",
'"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ',
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
"aardvark",
"😍😀🙌💃😍😍😍🙌",
"abcdefghijklmnopqrstuvwxyz"
]
print([
isCollapsible(x) for x in xs
])
# MAIN ---
if __name__ == '__main__':
main()
- Output:
[False, True, True, True, True, True, True, True, True, False]
Quackery[edit]
[ false -1 rot
witheach
[ 2dup = iff
[ drop dip not
conclude ]
else nip ]
drop ] is collapsible ( $ --> b )
[ [] -1 rot
witheach
[ 2dup = iff drop
else
[ nip dup dip join ] ]
drop ] is collapse ( $ --> $ )
[ dup collapsible iff
[ dup collapse
swap 2 ]
else
[ say "(Not collapsible.)" cr
1 ]
times
[ say "<<<"
dup echo$
say ">>>" cr
say " Length: "
size echo
say " characters" cr cr ]
cr ] is task ( $ --> )
$ "" task
$ '"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ' task
$ "..1111111111111111111111111111111111111111111111111111111111111117777888" task
$ "I never give 'em hell, I just tell the truth, and they think it's hell. " task
$ " --- Harry S Truman " task
- Output:
(Not collapsible.) <<<>>> Length: 0 characters <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> Length: 72 characters <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> Length: 70 characters <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> Length: 72 characters <<<.178>>> Length: 4 characters <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> Length: 72 characters <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> Length: 69 characters <<< --- Harry S Truman >>> Length: 72 characters <<< - Hary S Truman >>> Length: 17 characters
Raku[edit]
(formerly Perl 6)
Technically, the task is asking for a boolean. "Determine if a string is collapsible" is answerable with True/False, so return a boolean as well.
map {
my $squish = .comb.squish.join;
printf "\nLength: %2d <<<%s>>>\nCollapsible: %s\nLength: %2d <<<%s>>>\n",
.chars, $_, .chars != $squish.chars, $squish.chars, $squish
}, lines
q:to/STRINGS/;
"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln
..1111111111111111111111111111111111111111111111111111111111111117777888
I never give 'em hell, I just tell the truth, and they think it's hell.
--- Harry S Truman
The American people have a right to know if their president is a crook.
--- Richard Nixon
AАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑ
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
STRINGS
- Output:
Length: 0 <<<>>> Collapsible: False Length: 0 <<<>>> Length: 72 <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> Collapsible: True Length: 70 <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> Length: 72 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> Collapsible: True Length: 4 <<<.178>>> Length: 72 <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> Collapsible: True Length: 69 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> Length: 72 <<< --- Harry S Truman >>> Collapsible: True Length: 17 <<< - Hary S Truman >>> Length: 72 <<<The American people have a right to know if their president is a crook. >>> Collapsible: True Length: 71 <<<The American people have a right to know if their president is a crok. >>> Length: 72 <<< --- Richard Nixon >>> Collapsible: True Length: 17 <<< - Richard Nixon >>> Length: 72 <<<AАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑ>>> Collapsible: False Length: 72 <<<AАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑAАΑ>>> Length: 72 <<<AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA>>> Collapsible: True Length: 1 <<<A>>>
REXX[edit]
/*REXX program "collapses" all immediately repeated characters in a string (or strings).*/
@.= /*define a default for the @. array. */
parse arg x /*obtain optional argument from the CL.*/
if x\='' then @.1= x /*if user specified an arg, use that. */
else do; @.1=
@.2= '"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln '
@.3= ..1111111111111111111111111111111111111111111111111111111111111117777888
@.4= "I never give 'em hell, I just tell the truth, and they think it's hell. "
@.5= ' --- Harry S Truman '
end
do j=1; L= length(@.j) /*obtain the length of an array element*/
say copies('═', 105) /*show a separator line between outputs*/
if j>1 & L==0 then leave /*if arg is null and J>1, then leave. */
new= collapse(@.j)
say 'string' word("isn't is",1+collapsible) 'collapsible' /*display semaphore value*/
say ' length='right(L, 3) " input=«««" || @.j || '»»»'
w= length(new)
say ' length='right(w, 3) " output=«««" || new || '»»»'
end /*j*/
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
collapse: procedure expose collapsible; parse arg y 1 $ 2 /*get the arg; get 1st char. */
do k=2 to length(y) /*traipse through almost all the chars.*/
_= substr(y, k, 1) /*pick a character from Y (1st arg). */
if _==right($, 1) then iterate /*Is this the same character? Skip it.*/
$= $ || _ /*append the character, it's different.*/
end /*j*/
collapsible= y\==$; return $ /*set boolean to true if collapsible.*/
- output when using the internal default inputs:
═════════════════════════════════════════════════════════════════════════════════════════════════════════
string isn't collapsible
length= 0 input=«««»»»
length= 0 output=«««»»»
═════════════════════════════════════════════════════════════════════════════════════════════════════════
string is collapsible
length= 72 input=«««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»»
length= 70 output=«««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»»
═════════════════════════════════════════════════════════════════════════════════════════════════════════
string is collapsible
length= 72 input=«««..1111111111111111111111111111111111111111111111111111111111111117777888»»»
length= 4 output=«««.178»»»
═════════════════════════════════════════════════════════════════════════════════════════════════════════
string is collapsible
length= 72 input=«««I never give 'em hell, I just tell the truth, and they think it's hell. »»»
length= 69 output=«««I never give 'em hel, I just tel the truth, and they think it's hel. »»»
═════════════════════════════════════════════════════════════════════════════════════════════════════════
string is collapsible
length= 72 input=««« --- Harry S Truman »»»
length= 17 output=««« - Hary S Truman »»»
═════════════════════════════════════════════════════════════════════════════════════════════════════════
Ring[edit]
load "stdlib.ring"
see "working..." + nl + nl
str = ["The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"I never give 'em hell, I just tell the truth, and they think it's hell.",
"..1111111111111111111111111111111111111111111111111111111111111117777888"]
strsave = str
for n = 1 to len(str)
for m = 1 to len(str[n])-1
if substr(str[n],m,1) = substr(str[n],m+1,1)
str[n] = left(str[n],m) + right(str[n],len(str[n])-m-1)
for p = len(str[n]) to 2 step -1
if substr(str[n],p,1) = substr(str[n],p-1,1)
str[n] = left(str[n],p-1) + right(str[n],len(str[n])-p)
ok
next
ok
next
next
for n = 1 to len(str)
see "" + len(strsave[n]) + "«««" + strsave[n] + "»»»" + nl
see "" + len(str[n]) + "«««" + str[n] + "»»»" + nl + nl
next
see "done..." + nl
Output:
working... 80«««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» 77«««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» 71«««I never give 'em hell, I just tell the truth, and they think it's hell.»»» 68«««I never give 'em hel, I just tel the truth, and they think it's hel.»»» 72«««..1111111111111111111111111111111111111111111111111111111111111117777888»»» 4«««.178»»» done...
Ruby[edit]
This is built in since at least a decade under the method name 'squeeze'. squeeze(" ") would only squeeze spaces.
strings = ["",
'"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ',
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
"aardvark",
"😍😀🙌💃😍😍😍🙌",]
strings.each do |str|
puts "«««#{str}»»» (size #{str.size})"
ssq = str.squeeze
puts "«««#{ssq}»»» (size #{ssq.size})"
puts
end
- Output:
«««»»» (size 0) «««»»» (size 0) «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» (size 72) «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» (size 70) «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» (size 72) «««.178»»» (size 4) «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» (size 72) «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» (size 69) ««« --- Harry S Truman »»» (size 72) ««« - Hary S Truman »»» (size 17) «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» (size 80) «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» (size 77) «««headmistressship»»» (size 16) «««headmistreship»»» (size 14) «««aardvark»»» (size 8) «««ardvark»»» (size 7) «««😍😀🙌💃😍😍😍🙌»»» (size 8) «««😍😀🙌💃😍🙌»»» (size 6)
Rust[edit]
fn collapse_string(val: &str) -> String {
let mut output = String::new();
let mut chars = val.chars().peekable();
while let Some(c) = chars.next() {
while let Some(&b) = chars.peek() {
if b == c {
chars.next();
} else {
break;
}
}
output.push(c);
}
output
}
fn main() {
let tests = [
"122333444455555666666777777788888888999999999",
"",
"\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ",
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
];
for s in &tests {
println!("Old: {:>3} <<<{}>>>", s.len(), s);
let collapsed = collapse_string(s);
println!("New: {:>3} <<<{}>>>", collapsed.len(), collapsed);
println!();
}
}
- Output:
Old: 45 <<<122333444455555666666777777788888888999999999>>> New: 9 <<<123456789>>> Old: 0 <<<>>> New: 0 <<<>>> Old: 72 <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> New: 70 <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> Old: 72 <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> New: 4 <<<.178>>> Old: 72 <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> New: 69 <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> Old: 72 <<< --- Harry S Truman >>> New: 17 <<< - Hary S Truman >>> Old: 80 <<<The better the 4-wheel drive, the further you'll be from help when ya get stuck!>>> New: 77 <<<The beter the 4-whel drive, the further you'l be from help when ya get stuck!>>> Old: 16 <<<headmistressship>>> New: 14 <<<headmistreship>>>
Scala[edit]
Pure imperative programming 😃[edit]
object CollapsibleString {
/**Collapse a string (if possible)*/
def collapseString (s : String) : String = {
var res = s
var isOver = false
var i = 0
if(res.size == 0) res
else while(!isOver){
if(res(i) == res(i+1)){
res = res.take(i) ++ res.drop(i+1)
i-=1
}
i+=1
if(i==res.size-1) isOver = true
}
res
}
/**Check if a string is collapsible*/
def isCollapsible (s : String) : Boolean = collapseString(s).length != s.length
/**Display results as asked in the task*/
def reportResults (s : String) : String = {
val sCollapsed = collapseString(s)
val originalRes = "ORIGINAL : length = " + s.length() + ", string = «««" + s + "»»»"
val collapsedRes = "COLLAPSED : length = " + sCollapsed.length() + ", string = «««" + sCollapsed + "»»»"
//In order to avoid useless computations, the function isCollapsible isn't called
if(s.length != sCollapsed.length) originalRes + "\n" + collapsedRes + "\n" + "This string IS collapsible !"
else originalRes + "\n" + collapsedRes + "\n" + "This string is NOT collapsible !"
}
def main(args: Array[String]): Unit = {
println(reportResults(""))
println("------------")
println(reportResults("\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln "))
println("------------")
println(reportResults("..1111111111111111111111111111111111111111111111111111111111111117777888"))
println("------------")
println(reportResults("I never give 'em hell, I just tell the truth, and they think it's hell. "))
println("------------")
println(reportResults(" --- Harry S Truman "))
println("------------")
println(reportResults("The better the 4-wheel drive, the further you'll be from help when ya get stuck!"))
println("------------")
println(reportResults("headmistressship"))
println("------------")
println(reportResults("aardvark"))
}
}
- Output:
ORIGINAL : length = 0, string = «««»»» COLLAPSED : length = 0, string = «««»»» This string is NOT collapsible ! ------------ ORIGINAL : length = 72, string = «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» COLLAPSED : length = 70, string = «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» This string IS collapsible ! ------------ ORIGINAL : length = 72, string = «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» COLLAPSED : length = 4, string = «««.178»»» This string IS collapsible ! ------------ ORIGINAL : length = 72, string = «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» COLLAPSED : length = 69, string = «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» This string IS collapsible ! ------------ ORIGINAL : length = 72, string = ««« --- Harry S Truman »»» COLLAPSED : length = 17, string = ««« - Hary S Truman »»» This string IS collapsible ! ------------ ORIGINAL : length = 80, string = «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» COLLAPSED : length = 77, string = «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» This string IS collapsible ! ------------ ORIGINAL : length = 16, string = «««headmistressship»»» COLLAPSED : length = 14, string = «««headmistreship»»» This string IS collapsible ! ------------ ORIGINAL : length = 8, string = «««aardvark»»» COLLAPSED : length = 7, string = «««ardvark»»» This string IS collapsible !
Sidef[edit]
func squeeze(str) {
str.gsub(/(.)\1+/, {|s1| s1 })
}
var strings = ["",
'"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ',
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
"aardvark",
"😍😀🙌💃😍😍😍🙌"]
strings.each {|str|
var ssq = squeeze(str)
say "«««#{str}»»» (length: #{str.len})"
say "«««#{ssq}»»» (length: #{ssq.len})\n"
}
- Output:
«««»»» (length: 0) «««»»» (length: 0) «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» (length: 72) «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» (length: 70) «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» (length: 72) «««.178»»» (length: 4) «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» (length: 72) «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» (length: 69) ««« --- Harry S Truman »»» (length: 72) ««« - Hary S Truman »»» (length: 17) «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» (length: 80) «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» (length: 77) «««headmistressship»»» (length: 16) «««headmistreship»»» (length: 14) «««aardvark»»» (length: 8) «««ardvark»»» (length: 7) «««😍😀🙌💃😍😍😍🙌»»» (length: 8) «««😍😀🙌💃😍🙌»»» (length: 6)
Smalltalk[edit]
#(
'The better the 4-wheel drive, the further you''ll be from help when ya get stuck!'
'headmistressship'
'aardvark'
'😍😀🙌💃😍😍😍🙌'
) do:[:eachWord |
|shortened|
shortened :=
String streamContents:[:out |
eachWord inject:nil into:[:prev :this |
prev ~= this ifTrue:[out nextPut:this].
this
]
].
Transcript
showCR:( eachWord,'(length:',eachWord size,')' );
showCR:( shortened,'(length:',shortened size,')' ).
]
- Output:
The better the 4-wheel drive, the further you'll be from help when ya get stuck!(length:80) The beter the 4-whel drive, the further you'l be from help when ya get stuck!(length:77) headmistressship(length:16) headmistreship(length:14) aardvark(length:8) ardvark(length:7) 😍😀🙌💃😍😍😍🙌(length:8) 😍😀🙌💃😍🙌(length:6)
Swift[edit]
let strings = [
"",
#""If I were two-faced, would I be wearing this one?" --- Abraham Lincoln "#,
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
"aardvark",
"😍😀🙌💃😍😍😍🙌"
]
let collapsedStrings = strings.map { $0.replacingOccurrences( of: #"(.)\1*"#, with: "$1", options: .regularExpression)}
for (original, collapsed) in zip(strings, collapsedStrings) {
print (String(format: "%03d «%@»\n%03d «%@»\n", original.count, original, collapsed.count, collapsed))
}
- Output:
000 «» 000 «» 072 «"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln » 070 «"If I were two-faced, would I be wearing this one?" - Abraham Lincoln » 072 «..1111111111111111111111111111111111111111111111111111111111111117777888» 004 «.178» 072 «I never give 'em hell, I just tell the truth, and they think it's hell. » 069 «I never give 'em hel, I just tel the truth, and they think it's hel. » 072 « --- Harry S Truman » 017 « - Hary S Truman » 080 «The better the 4-wheel drive, the further you'll be from help when ya get stuck!» 077 «The beter the 4-whel drive, the further you'l be from help when ya get stuck!» 016 «headmistressship» 014 «headmistreship» 008 «aardvark» 007 «ardvark» 008 «😍😀🙌💃😍😍😍🙌» 006 «😍😀🙌💃😍🙌»
Tcl[edit]
Please note the ;# ' comments, there appears to be a syntax hightlighting bug with RC
set test {
{}
{"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln }
{..1111111111111111111111111111111111111111111111111111111111111117777888}
{I never give 'em hell, I just tell the truth, and they think it's hell. } ;# '
{ --- Harry S Truman }
{The better the 4-wheel drive, the further you'll be from help when ya get stuck!} ;# '
{headmistressship}
}
foreach {str} $test {
# Uses regexp lookbehind to detect repeated characters
set sub [regsub -all {(.)(\1+)} $str {\1}]
# Output
puts [format "Original (length %3d): %s" [string length $str] $str]
puts [format "Subbed (length %3d): %s" [string length $sub] $sub]
puts ----------------------
}
- Output:
Original (length 0): Subbed (length 0): ---------------------- Original (length 72): "If I were two-faced, would I be wearing this one?" --- Abraham Lincoln Subbed (length 70): "If I were two-faced, would I be wearing this one?" - Abraham Lincoln ---------------------- Original (length 72): ..1111111111111111111111111111111111111111111111111111111111111117777888 Subbed (length 4): .178 ---------------------- Original (length 72): I never give 'em hell, I just tell the truth, and they think it's hell. Subbed (length 69): I never give 'em hel, I just tel the truth, and they think it's hel. ---------------------- Original (length 72): --- Harry S Truman Subbed (length 17): - Hary S Truman ---------------------- Original (length 80): The better the 4-wheel drive, the further you'll be from help when ya get stuck! Subbed (length 77): The beter the 4-whel drive, the further you'l be from help when ya get stuck! ---------------------- Original (length 16): headmistressship Subbed (length 14): headmistreship ----------------------
Visual Basic .NET[edit]
Module Module1
Function Collapse(s As String) As String
If String.IsNullOrEmpty(s) Then
Return ""
End If
Return s(0) + New String(Enumerable.Range(1, s.Length - 1).Where(Function(i) s(i) <> s(i - 1)).Select(Function(i) s(i)).ToArray)
End Function
Sub Main()
Dim input() = {
"",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
ControlChars.Quote + "If I were two-faced, would I be wearing this one?" + ControlChars.Quote + " --- Abraham Lincoln ",
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman "
}
For Each s In input
Console.WriteLine($"old: {s.Length} «««{s}»»»")
Dim c = Collapse(s)
Console.WriteLine($"new: {c.Length} «««{c}»»»")
Next
End Sub
End Module
- Output:
old: 0 «««»»» new: 0 «««»»» old: 80 «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» new: 77 «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» old: 16 «««headmistressship»»» new: 14 «««headmistreship»»» old: 72 «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» new: 70 «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» old: 72 «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» new: 4 «««.178»»» old: 72 «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» new: 69 «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» old: 72 ««« --- Harry S Truman »»» new: 17 ««« - Hary S Truman »»»
VBA[edit]
Function :
Function Collapse(strIn As String) As String
Dim i As Long, strOut As String
If Len(strIn) > 0 Then
strOut = Mid$(strIn, 1, 1)
For i = 2 To Len(strIn)
If Mid$(strIn, i, 1) <> Mid$(strIn, i - 1, 1) Then
strOut = strOut & Mid$(strIn, i, 1)
End If
Next i
End If
Collapse = strOut
End Function
To Call :
Sub CallCollapse()
Dim S As String
S = vbNullString
Debug.Print "String : <<<" & S & ">>>", "Lenght : " & Len(S)
Debug.Print "Collapsed : <<<" & Collapse(S) & ">>>", "Lenght : " & Len(Collapse(S))
S = """If I were two-faced, would I be wearing this one?"" --- Abraham Lincoln "
Debug.Print "String : <<<" & S & ">>>", "Lenght : " & Len(S)
Debug.Print "Collapsed : <<<" & Collapse(S) & ">>>", "Lenght : " & Len(Collapse(S))
S = "..1111111111111111111111111111111111111111111111111111111111111117777888"
Debug.Print "String : <<<" & S & ">>>", "Lenght : " & Len(S)
Debug.Print "Collapsed : <<<" & Collapse(S) & ">>>", "Lenght : " & Len(Collapse(S))
S = "I never give 'em hell, I just tell the truth, and they think it's hell. "
Debug.Print "String : <<<" & S & ">>>", "Lenght : " & Len(S)
Debug.Print "Collapsed : <<<" & Collapse(S) & ">>>", "Lenght : " & Len(Collapse(S))
S = " --- Harry S Truman "
Debug.Print "String : <<<" & S & ">>>", "Lenght : " & Len(S)
Debug.Print "Collapsed : <<<" & Collapse(S) & ">>>", "Lenght : " & Len(Collapse(S))
End Sub
- Output:
String : <<<>>> Lenght : 0 Collapsed : <<<>>> Lenght : 0 String : <<<"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln >>> Lenght : 72 Collapsed : <<<"If I were two-faced, would I be wearing this one?" - Abraham Lincoln >>> Lenght : 70 String : <<<..1111111111111111111111111111111111111111111111111111111111111117777888>>> Lenght : 72 Collapsed : <<<.178>>> Lenght : 4 String : <<<I never give 'em hell, I just tell the truth, and they think it's hell. >>> Lenght : 72 Collapsed : <<<I never give 'em hel, I just tel the truth, and they think it's hel. >>> Lenght : 69 String : <<< --- Harry S Truman >>> Lenght : 72 Collapsed : <<< - Hary S Truman >>> Lenght : 17
Wren[edit]
import "/fmt" for Fmt
// Returns collapsed string, original and new lengths in
// unicode code points (not normalized).
var collapse = Fn.new { |s|
var c = s.codePoints.toList
var le = c.count
if (le < 2) return [s, le, le]
for (i in le-2..0) {
if (c[i] == c[i+1]) c.removeAt(i)
}
var cc = c.reduce("") { |acc, cp| acc + String.fromCodePoint(cp) }
return [cc, le, cc.count]
}
var strings = [
"",
"\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ",
"..1111111111111111111111111111111111111111111111111111111111111117777888",
"I never give 'em hell, I just tell the truth, and they think it's hell. ",
" --- Harry S Truman ",
"The better the 4-wheel drive, the further you'll be from help when ya get stuck!",
"headmistressship",
"aardvark",
"😍😀🙌💃😍😍😍🙌"
]
for (s in strings) {
var r = collapse.call(s)
System.print("original : length = %(Fmt.d(2, r[1])), string = «««%(s)»»»")
System.print("collapsed: length = %(Fmt.d(2, r[2])), string = «««%(r[0])»»»\n")
}
- Output:
original : length = 0, string = «««»»» collapsed: length = 0, string = «««»»» original : length = 72, string = «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» collapsed: length = 70, string = «««"If I were two-faced, would I be wearing this one?" - Abraham Lincoln »»» original : length = 72, string = «««..1111111111111111111111111111111111111111111111111111111111111117777888»»» collapsed: length = 4, string = «««.178»»» original : length = 72, string = «««I never give 'em hell, I just tell the truth, and they think it's hell. »»» collapsed: length = 69, string = «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» original : length = 72, string = ««« --- Harry S Truman »»» collapsed: length = 17, string = ««« - Hary S Truman »»» original : length = 80, string = «««The better the 4-wheel drive, the further you'll be from help when ya get stuck!»»» collapsed: length = 77, string = «««The beter the 4-whel drive, the further you'l be from help when ya get stuck!»»» original : length = 16, string = «««headmistressship»»» collapsed: length = 14, string = «««headmistreship»»» original : length = 8, string = «««aardvark»»» collapsed: length = 7, string = «««ardvark»»» original : length = 8, string = «««😍😀🙌💃😍😍😍🙌»»» collapsed: length = 6, string = «««😍😀🙌💃😍🙌»»»
zkl[edit]
fcn collapsible(str){ // no Unicode
sink:=Sink(String);
str.reduce('wrap(c1,c2){ if(c1!=c2) sink.write(c2); c2 },""); // prime with \0
cstr:=sink.close();
return(str.len()!=cstr.len(), cstr);
}
strings:=
0'^
"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln
..1111111111111111111111111111111111111111111111111111111111111117777888
I never give 'em hell, I just tell the truth, and they think it's hell.
--- Harry S Truman
The American people have a right to know if their president is a crook.
--- Richard Nixon
The better the 4-wheel drive, the further you'll be from help when ya get stuck!
headmistressship
aardvark^
.split("\n");
#<<<
foreach s in (strings){
println("Before: %3d >>>%s<<<".fmt(s.len(),s));
_,cstr:=collapsible(s);
println("After: %3d >>>%s<<<\n".fmt(cstr.len(),cstr));
}
- Output:
Before: 0 >>><<< After: 0 >>><<< Before: 72 >>>"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln <<< After: 70 >>>"If I were two-faced, would I be wearing this one?" - Abraham Lincoln <<< Before: 72 >>>..1111111111111111111111111111111111111111111111111111111111111117777888<<< After: 4 >>>.178<<< Before: 72 >>>I never give 'em hell, I just tell the truth, and they think it's hell. <<< After: 69 >>>I never give 'em hel, I just tel the truth, and they think it's hel. <<< Before: 72 >>> --- Harry S Truman <<< After: 17 >>> - Hary S Truman <<< Before: 72 >>>The American people have a right to know if their president is a crook. <<< After: 71 >>>The American people have a right to know if their president is a crok. <<< Before: 72 >>> --- Richard Nixon <<< After: 17 >>> - Richard Nixon <<< Before: 80 >>>The better the 4-wheel drive, the further you'll be from help when ya get stuck!<<< After: 77 >>>The beter the 4-whel drive, the further you'l be from help when ya get stuck!<<< Before: 16 >>>headmistressship<<< After: 14 >>>headmistreship<<< Before: 8 >>>aardvark<<< After: 7 >>>ardvark<<<
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