Roman numerals/Encode: Difference between revisions
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=={{header|C}}== |
=={{header|C}}== |
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<c>#include <stdlib.h> |
<lang c>#include <stdlib.h> |
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#include <stdio.h> |
#include <stdio.h> |
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{roman(buffer, i); |
{roman(buffer, i); |
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printf("%4d: %s\n", i, buffer);} |
printf("%4d: %s\n", i, buffer);} |
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return 1;}</ |
return 1;}</lang> |
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An alternative version which builds the string backwards. <c>char *ToRoman(int num, char *buf, int buflen) |
An alternative version which builds the string backwards. <lang c>char *ToRoman(int num, char *buf, int buflen) |
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{ |
{ |
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static char *romanDgts = "ivxlcdmVXLCDM_"; |
static char *romanDgts = "ivxlcdmVXLCDM_"; |
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} |
} |
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return roman; |
return roman; |
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}</ |
}</lang> |
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=={{header|Common Lisp}}== |
=={{header|Common Lisp}}== |
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=={{header|D}}== |
=={{header|D}}== |
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This implementation in generally follows the rules implied by [[wp:Roman_numerals#Modern_Roman_numerals|Modern Roman numerals]], with some irregularity depend on whether numerals larger than '''M'''(1000) is used, eg. 4000 is converted to '''MV'''' if '''V'''' is used, '''MMMM''' if not. |
This implementation in generally follows the rules implied by [[wp:Roman_numerals#Modern_Roman_numerals|Modern Roman numerals]], with some irregularity depend on whether numerals larger than '''M'''(1000) is used, eg. 4000 is converted to '''MV'''' if '''V'''' is used, '''MMMM''' if not. |
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<d>module roman ; |
<lang d>module roman ; |
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import std.stdio ; |
import std.stdio ; |
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foreach(x ; test) |
foreach(x ; test) |
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writefln("%20s - %s", x, toRoman(x)) ; |
writefln("%20s - %s", x, toRoman(x)) ; |
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}</ |
}</lang> |
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=={{header|Factor}}== |
=={{header|Factor}}== |
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The helper function <tt>copies</tt> is added since Java does not support String multiplication. The conversion function returns <tt>null</tt> for a negative number, since Java does not have unsigned primitives. |
The helper function <tt>copies</tt> is added since Java does not support String multiplication. The conversion function returns <tt>null</tt> for a negative number, since Java does not have unsigned primitives. |
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<java>public class RN{ |
<lang java>public class RN{ |
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public static void main(String args[]){ |
public static void main(String args[]){ |
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System.out.println(roman(1999)); |
System.out.println(roman(1999)); |
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return result; |
return result; |
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} |
} |
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}</ |
}</lang> |
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Output: |
Output: |
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MCMXCIX |
MCMXCIX |
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With an explicit decimal digit representation list: |
With an explicit decimal digit representation list: |
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<ocaml> |
<lang ocaml> |
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let digit x y z = function |
let digit x y z = function |
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1 -> [x] |
1 -> [x] |
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else |
else |
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digit 'I' 'V' 'X' x |
digit 'I' 'V' 'X' x |
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</ |
</lang> |
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Output: |
Output: |
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cis |
cis |
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=={{header|Python}}== |
=={{header|Python}}== |
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<python>roman = "MDCLXVmdclxvi"; # UPPERCASE for thousands # |
<lang python>roman = "MDCLXVmdclxvi"; # UPPERCASE for thousands # |
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adjust_roman = "CCXXmmccxxii"; |
adjust_roman = "CCXXmmccxxii"; |
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arabic = (1000000, 500000, 100000, 50000, 10000, 5000, 1000, 500, 100, 50, 10, 5, 1); |
arabic = (1000000, 500000, 100000, 50000, 10000, 5000, 1000, 500, 100, 50, 10, 5, 1); |
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for val in test: |
for val in test: |
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print '%d - %s'%(val, arabic_to_roman(val)) |
print '%d - %s'%(val, arabic_to_roman(val)) |
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</ |
</lang> |
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An alternative which uses the divmod() function <python>romanDgts= 'ivxlcdmVXLCDM_' |
An alternative which uses the divmod() function <lang python>romanDgts= 'ivxlcdmVXLCDM_' |
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def ToRoman(num): |
def ToRoman(num): |
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else: |
else: |
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namoR += r*romanDgts[rdix] + (romanDgts[rdix+1] if(v==1) else '') |
namoR += r*romanDgts[rdix] + (romanDgts[rdix+1] if(v==1) else '') |
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return namoR[-1::-1]</ |
return namoR[-1::-1]</lang> |
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=={{header|Ruby}}== |
=={{header|Ruby}}== |
Revision as of 15:49, 3 February 2009
You are encouraged to solve this task according to the task description, using any language you may know.
Create a function taking a positive integer as its parameter and returning a string containing the Roman Numeral representation of that integer.
Modern Roman numerals are written by expressing each digit separately starting with the left most digit and skipping any digit with a value of zero. In Roman numerals 1990 is rendered: 1000=M, 900=CM, 90=XC; resulting in MCMXC. 2008 is written as 2000=MM, 8=VIII; or MMVIII. 1666 uses each Roman symbol in descending order: MDCLXVI.
Ada
<Ada> with Ada.Text_IO; use Ada.Text_IO;
procedure Roman_Numeral_Test is
function To_Roman (Number : Positive) return String is subtype Digit is Integer range 0..9; function Roman (Figure : Digit; I, V, X : Character) return String is begin case Figure is when 0 => return ""; when 1 => return "" & I; when 2 => return I & I; when 3 => return I & I & I; when 4 => return I & V; when 5 => return "" & V; when 6 => return V & I; when 7 => return V & I & I; when 8 => return V & I & I & I; when 9 => return I & X; end case; end Roman; begin return Roman (Number / 1000, 'M', 'M', 'M') & Roman (Number / 100 mod 10, 'C', 'D', 'M') & Roman (Number / 10 mod 10, 'X', 'L', 'C') & Roman (Number mod 10, 'I', 'V', 'X'); end To_Roman;
begin
Put_Line (To_Roman (1999)); Put_Line (To_Roman (25)); Put_Line (To_Roman (944));
end Roman_Numeral_Test; </Ada> Output:
MCMXCIX XXV CMXLIV
ALGOL 68
[]CHAR roman = "MDCLXVmdclxvi"; # UPPERCASE for thousands # []CHAR adjust roman = "CCXXmmccxxii"; []INT arabic = (1000000, 500000, 100000, 50000, 10000, 5000, 1000, 500, 100, 50, 10, 5, 1); []INT adjust arabic = (100000, 100000, 10000, 10000, 1000, 1000, 100, 100, 10, 10, 1, 1, 0); PROC arabic to roman = (INT dclxvi)STRING: ( INT in := dclxvi; # 666 # STRING out := ""; FOR scale TO UPB roman WHILE in /= 0 DO INT multiples = in OVER arabic[scale]; in -:= arabic[scale] * multiples; out +:= roman[scale] * multiples; IF in >= -adjust arabic[scale] + arabic[scale] THEN in -:= -adjust arabic[scale] + arabic[scale]; out +:= adjust roman[scale] + roman[scale] FI OD; out ); main:( []INT test = (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,25,30,40,50,60,69,70, 80,90,99,100,200,300,400,500,600,666,700,800,900,1000,1009,1444,1666,1945,1997,1999, 2000,2008,2500,3000,4000,4999,5000,6666,10000,50000,100000,500000,1000000,max int); FOR key TO UPB test DO INT val = test[key]; printf(($g" - "gl$, val, arabic to roman(val))) OD )
C
<lang c>#include <stdlib.h>
- include <stdio.h>
void roman(char *s, unsigned n) /* Writes the Roman numeral representing n into the buffer s. Handles up to n = 3999. Since C doesn't have exceptions, n = 0 causes the whole program to exit unsuccessfully. s should be have room for at least 16 characters, including the trailing null. */
{if (n == 0) {puts("Roman numeral for zero requested."); exit(EXIT_FAILURE);}
#define digit(loop, num, c) \ loop (n >= num) \ {*(s++) = c; \ n -= num;} #define digits(loop, num, c1, c2) \ loop (n >= num) \ {*(s++) = c1; \ *(s++) = c2; \ n -= num;}
digit ( while, 1000, 'M' ) digits ( if, 900, 'C', 'M' ) digit ( if, 500, 'D' ) digits ( if, 400, 'C', 'D' ) digit ( while, 100, 'C' ) digits ( if, 90, 'X', 'C' ) digit ( if, 50, 'L' ) digits ( if, 40, 'X', 'L' ) digit ( while, 10, 'X' ) digits ( if, 9, 'I', 'X' ) digit ( if, 5, 'V' ) digits ( if, 4, 'I', 'V' ) digit ( while, 1, 'I' )
#undef digit #undef digits *s = 0;}
int main(void)
{char buffer[16]; for (int i = 1 ; i < 4000 ; ++i) {roman(buffer, i); printf("%4d: %s\n", i, buffer);} return 1;}</lang>
An alternative version which builds the string backwards. <lang c>char *ToRoman(int num, char *buf, int buflen) {
static char *romanDgts = "ivxlcdmVXLCDM_"; char *roman = buf + buflen; int rdix, r, v; *--roman = '\0'; /* null terminate return string */ if (num >= 4000000) { printf("Number Too Big.\n"); return NULL; } for (rdix = 0; rdix < strlen(romanDgts); rdix += 2) { if (num == 0) break; v = (num % 10) / 5; r = num % 5; num = num / 10; if (r == 4) { if (roman < buf+2) { printf("Buffer too small."); return NULL; } *--roman = romanDgts[rdix+1+v]; *--roman = romanDgts[rdix]; } else { if (roman < buf+r+v) { printf("Buffer too small."); return NULL; } while(r-- > 0) { *--roman = romanDgts[rdix]; } if (v==1) { *--roman = romanDgts[rdix+1]; } } } return roman;
}</lang>
Common Lisp
(defun roman-numeral (n) (format nil "~@R" n))
D
This implementation in generally follows the rules implied by Modern Roman numerals, with some irregularity depend on whether numerals larger than M(1000) is used, eg. 4000 is converted to MV' if V' is used, MMMM if not. <lang d>module roman ; import std.stdio ;
const string[] Roman = ["V","X","L","C","D","M","I"] ; const int RLen = Roman.length - 1 ; const int[][] RDigit =
[[0],[0,0],[0,0,0],[0,1],[1],[1,0],[1,0,0],[1,0,0,0],[0,2],[0,0,0,0]] ;
const string[] Power = ["", "'","\"","`","~","^","#"] ; // arbitary _power_ symbols, or
// Power = ["1","2","3","4","5","6","7"] ; // for easier further processing
const int[][] Shift = [[0,0,0],[-1,0,0]] ;
string romanPart(int n, int part, bool extented) {
if (n == 0) return "" ; int[3] b ; b[1] = (2 * part) % RLen ; b[0] = part == 0 ? RLen : (RLen + b[1] - 1) % RLen ; b[2] = b[1] + 1 ; int power = part / 3 ; int[] shift = Shift[ b[1] == 0 && part != 0 ? 1 : 0] ; int[] Digit = !extented && n == 4 && part == 3 ? RDigit[$-1] : RDigit[n-1] ; string res ; foreach(inx ; Digit) res ~= Roman[b[inx]] ~ Power[power + shift[inx]] ; return res ;
} string toRoman(long n, bool extented = true) {
if(n < 0) throw new Exception("No negative Roman Numeral") ; if(n == 0) return "" ; if(!extented && n >= 5000) throw new Exception("Only smaller than 5000 allowed") ; string romans ; int part = 0 ; while (n > 0) { long m = n / 10 ; romans = romanPart(n - m*10, part, extented) ~ romans ; n = m ; part++ ; } return romans ;
} void main() {
auto test = [1L,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,25,30,40,50,60,69,70, 80,90,99,100,200,300,400,500,600,666,700,800,900,1000,1009,1444,1666,1945,1997, 1999, 2000,2008,2500,3000,4000,4999,5000,6666,10000,50000,100000,500000,1000000,long.max] ; foreach(x ; test) writefln("%20s - %s", x, toRoman(x)) ;
}</lang>
Factor
A roman numeral library ships with Factor.
USE: roman ( scratchpad ) 3333 >roman . "mmmcccxxxiii"
: roman-digits ( -- seq ) { "m" "cm" "d" "cd" "c" "xc" "l" "xl" "x" "ix" "v" "iv" "i" } ; : roman-values ( -- seq ) { 1000 900 500 400 100 90 50 40 10 9 5 4 1 } ; ERROR: roman-range-error n ; : roman-range-check ( n -- ) dup 1 3999 between? [ drop ] [ roman-range-error ] if ; : (>roman) ( n -- ) roman-values roman-digits [ [ /mod swap ] dip <repetition> concat % ] 2each drop ; : >roman ( n -- str ) dup roman-range-check [ (>roman) ] "" make ;
Forth
: vector create ( n -- ) 0 do , loop does> ( n -- ) swap cells + @ execute ; \ these are ( numerals -- numerals ) : .I dup c@ emit ; : .V dup 1 + c@ emit ; : .X dup 2 + c@ emit ; \ these are ( numerals -- ) :noname .I .X drop ; :noname .V .I .I .I drop ; :noname .V .I .I drop ; :noname .V .I drop ; :noname .V drop ; :noname .I .V drop ; :noname .I .I .I drop ; :noname .I .I drop ; :noname .I drop ; ' drop \ 0: no output 10 vector .digit : roman-rec ( numerals n -- ) 10 /mod dup if >r over 2 + r> recurse else drop then .digit ; : .roman ( n -- ) dup 0 4000 within 0= if ." EX LIMITO!" exit then s" IVXLCDM" drop swap roman-rec ;
Fortran
MODULE Roman IMPLICIT NONE CONTAINS FUNCTION numerals(number) CHARACTER(15) :: numerals CHARACTER(4) :: thousand_str, hundred_str, ten_str, unit_str INTEGER :: number, thousands, hundreds, tens thousands = number / 1000 SELECT CASE (thousands) CASE(0) thousand_str = "" CASE(1:4) thousand_str = REPEAT(STRING="M", NCOPIES=thousands) END SELECT number = MOD(number, 1000) hundreds = number / 100 SELECT CASE (hundreds) CASE(0) hundred_str = "" CASE(1:3) hundred_str = REPEAT(STRING="C", NCOPIES=hundreds) CASE(4) hundred_str = "CD" CASE(5) hundred_str = "D" CASE(6:8) hundred_str = "D"//REPEAT(STRING="C", NCOPIES=hundreds-5) CASE(9) hundred_str = "CM" END SELECT number = MOD(number, 100) tens = number / 10 SELECT CASE (tens) CASE(0) ten_str = "" CASE(1:3) ten_str = REPEAT(STRING="X", NCOPIES=tens) CASE(4) ten_str = "XL" CASE(5) ten_str = "L" CASE(6:8) ten_str = "L"//REPEAT(STRING="X", NCOPIES=tens-5) CASE(9) ten_str = "XC" END SELECT number = MOD(number, 10) SELECT CASE (number) CASE(0) unit_str = "" CASE(1:3) unit_str = REPEAT(STRING="I", NCOPIES=number) CASE(4) unit_str = "IV" CASE(5) unit_str = "V" CASE(6:8) unit_str = "V"//REPEAT(STRING="I", NCOPIES=number-5) CASE(9) unit_str = "IX" END SELECT numerals = TRIM(thousand_str)//TRIM(hundred_str)//TRIM(ten_str)//TRIM(unit_str) END FUNCTION END MODULE PROGRAM ROMAN_TEST USE Roman WRITE(*,*) numerals(2008) WRITE(*,*) numerals(1666) WRITE(*,*) numerals(3888) END PROGRAM ROMAN_TEST
Output
MMVIII MDCLXVI MMMDCCCLXXXVIII
Haskell
With an explicit decimal digit representation list:
digit x y z k = [[x],[x,x],[x,x,x],[x,y],[y],[y,x],[y,x,x],[y,x,x,x],[x,z]] !! (fromInteger k - 1) toRoman :: Integer -> String toRoman 0 = "" toRoman x | x < 0 = error "Negative roman numeral" toRoman x | x >= 1000 = 'M' : toRoman (x - 1000) toRoman x | x >= 100 = digit 'C' 'D' 'M' q ++ toRoman r where (q,r) = x `divMod` 100 toRoman x | x >= 10 = digit 'X' 'L' 'C' q ++ toRoman r where (q,r) = x `divMod` 10 toRoman x = digit 'I' 'V' 'X' x
Output:
*Main> map toRoman [1999,25,944] ["MCMXCIX","XXV","CMXLIV"]
J
rfd obtains Roman numerals from decimals, and dfr decimals from Roman numerals.
dfr=: 3 : 0 i=. 'IVXLCDM' i. y d=. i{1 5 10 50 100 500 1000 +/d*_1^i<}.i,_1 ) r100 =. <;._1 ' C CC CCC CD D DC DCC DCCC CM' r10 =. <;._1 ' X XX XXX XL L LX LXX LXXX XC' r1 =. <;._1 ' I II III IV V VI VII VIII IX' R1000=: , r100 ,&.>/ r10 ,&.>/ r1 rfd=: 3 : 0 ('M'$~<.y%1000),R1000{::~1000|y )
Copied, with permission, from the J Wiki. Examples of use will be found there.
Java
The helper function copies is added since Java does not support String multiplication. The conversion function returns null for a negative number, since Java does not have unsigned primitives. <lang java>public class RN{ public static void main(String args[]){ System.out.println(roman(1999)); System.out.println(roman(25)); System.out.println(roman(954)); } public static String roman(long n){ if(n < 1) return null; String result = ""; if(n >= 1000){ result+= (copies("M",(n / 1000))); n%= 1000; } if(n >= 900){ result+= "CM"; n%= 900; } if(n >= 500){ result+= "D"; n%= 500; } if(n >= 400){ result+= "CD"; n%= 400; } if(n >= 100){ result+= (copies("C",(n / 100))); n%= 100; } if(n >= 90){ result+= "XC"; n%= 90; } if(n >= 50){ result+= "L"; n%= 50; } if(n >= 40){ result+= "XL"; n%= 40; } if(n >= 10){ result+= (copies("X",(n / 10))); n%= 10; } if(n == 9){ result+= "IX"; n= 0; } if(n >= 5){ result+= "V"; n%= 5; } if(n == 4){ result+= "IV"; n= 0; } result+= (copies("I",n)); return result; }
public static String copies(String a, int n){ String result = ""; for(int i= 0;i < n;i++,result+= a); return result; } }</lang> Output:
MCMXCIX XXV CMXLIV
Logo
make "patterns [[?] [? ?] [? ? ?] [? ?2] [?2] [?2 ?] [?2 ? ?] [?2 ? ? ?] [? ?3]] to digit :d :numerals if :d = 0 [output "||] output apply (sentence "\( "word (item :d :patterns) "\)) :numerals end to digits :n :numerals output word ifelse :n < 10 ["||] [digits int :n/10 bf bf :numerals] ~ digit modulo :n 10 :numerals end to roman :n if or :n < 0 :n >= 4000 [output [EX MODVS!]] output digits :n [I V X L C D M] end
print roman 1999 ; MCMXCIX print roman 25 ; XXV print roman 944 ; CMXLIV
OCaml
With an explicit decimal digit representation list:
<lang ocaml> let digit x y z = function
1 -> [x] | 2 -> [x;x] | 3 -> [x;x;x] | 4 -> [x;y] | 5 -> [y] | 6 -> [y;x] | 7 -> [y;x;x] | 8 -> [y;x;x;x] | 9 -> [x;z]
let rec to_roman x =
if x = 0 then [] else if x < 0 then invalid_arg "Negative roman numeral" else if x >= 1000 then 'M' :: to_roman (x - 1000) else if x >= 100 then digit 'C' 'D' 'M' (x / 100) @ to_roman (x mod 100) else if x >= 10 then digit 'X' 'L' 'C' (x / 10) @ to_roman (x mod 10) else digit 'I' 'V' 'X' x
</lang>
Output:
# to_roman 1999;; - : char list = ['M'; 'C'; 'M'; 'X'; 'C'; 'I'; 'X'] # to_roman 25;; - : char list = ['X'; 'X'; 'V'] # to_roman 944;; - : char list = ['C'; 'M'; 'X'; 'L'; 'I'; 'V']
Perl
Perligata outputs numbers in Arabic, but the verb come ("beautify") may be used to convert numbers to proper Roman numerals:
per quisque in I tum C conscribementum sic hoc tum duos multiplicamentum comementum egresso scribe. cis
Python
<lang python>roman = "MDCLXVmdclxvi"; # UPPERCASE for thousands # adjust_roman = "CCXXmmccxxii"; arabic = (1000000, 500000, 100000, 50000, 10000, 5000, 1000, 500, 100, 50, 10, 5, 1); adjust_arabic = (100000, 100000, 10000, 10000, 1000, 1000, 100, 100, 10, 10, 1, 1, 0);
def arabic_to_roman(dclxvi):
org = dclxvi; # 666 # out = ""; for scale,arabic_scale in enumerate(arabic): if org == 0: break multiples = org / arabic_scale; org -= arabic_scale * multiples; out += roman[scale] * multiples; if org >= -adjust_arabic[scale] + arabic_scale: org -= -adjust_arabic[scale] + arabic_scale; out += adjust_roman[scale] + roman[scale] return out
if __name__ == "__main__":
test = (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,25,30,40,50,60,69,70, 80,90,99,100,200,300,400,500,600,666,700,800,900,1000,1009,1444,1666,1945,1997,1999, 2000,2008,2500,3000,4000,4999,5000,6666,10000,50000,100000,500000,1000000); for val in test: print '%d - %s'%(val, arabic_to_roman(val))
</lang> An alternative which uses the divmod() function <lang python>romanDgts= 'ivxlcdmVXLCDM_'
def ToRoman(num):
namoR = if num >=4000000: print 'Too Big -' return '-----' for rdix in range(0, len(romanDgts), 2): if num==0: break num,r = divmod(num,10) v,r = divmod(r, 5) if r==4: namoR += romanDgts[rdix+1+v] + romanDgts[rdix] else: namoR += r*romanDgts[rdix] + (romanDgts[rdix+1] if(v==1) else ) return namoR[-1::-1]</lang>
Ruby
Roman numeral generation was used as an example for demonstrating Test Driven Development in Ruby.