Decimal to roman converter

From CodeCodex

Implementations[edit]

PHP[edit]

<?PHP 
/*
Decimal <--> Roman 1.1
Written by: Rasmus Rimestad 
Email: rasmusr@online.no
Homepage: http://dikt.cjb.net
Written: XXIV.VII.MMI

This file includes two functions

string dec2roman (integer $number)
where $number is a number you want to convert to a roman one.

integer roman2dec (string $linje)
where $linje is the roman number you want to conver to an integer.
*/

function dec2roman ($number) {

	# Making input compatible with script.
	$number = floor($number);
	if($number < 0) {
		$linje = "-";
		$number = abs($number);
	}
	
	# Defining arrays
	$romanNumbers = array(1000, 500, 100, 50, 10, 5, 1);
	$romanLettersToNumbers = array("M" => 1000, "D" => 500, "C" => 100, "L" => 50, "X" => 10, "V" => 5, "I" => 1);
	$romanLetters = array_keys($romanLettersToNumbers);
	
	# Looping through and adding letters.
	while ($number) {
		for($pos = 0; $pos <= 6; $pos++) {
			
			# Dividing the remaining number with one of the roman numbers.
			$dividend = $number / $romanNumbers[$pos];

			# If that division is >= 1, round down, and add that number of letters to the string.
			if($dividend >= 1) {
				$linje .= str_repeat($romanLetters[$pos], floor($dividend));

				# Reduce the number to reflect what is left to make roman of.
				$number -= floor($dividend) * $romanNumbers[$pos];
			}
		}
	}


	# If I find 4 instances of the same letter, this should be done in a different way.
	# Then, subtract instead of adding (smaller number in front of larger).
	$numberOfChanges = 1;
	while($numberOfChanges) {
		$numberOfChanges = 0;

		for($start = 0; $start < strlen($linje); $start++) {
			$chunk = substr($linje, $start, 1);
			if($chunk == $oldChunk && $chunk != "M") {
				$appearance++;
			} else {
				$oldChunk = $chunk;
				$appearance = 1;
			}

			# Was there found 4 instances.
			if($appearance == 4) {
				$firstLetter = substr($linje, $start - 4, 1);
				$letter = $chunk;
				$sum = $firstNumber + $letterNumber * 4;

				$pos = array_search($letter, $romanLetters);

				# Are the four digits to be calculated together with the one before? (Example yes: VIIII = IX Example no: MIIII = MIV
				# This is found by checking if the digit before the first of the four instances is the one which is before the digits in the order
				# of the roman number. I.e. MDCLXVI.

				if($romanLetters[$pos - 1] == $firstLetter) {
					$oldString = $firstLetter . str_repeat($letter, 4);
					$newString = $letter . $romanLetters[$pos - 2];
				} else {
					$oldString = str_repeat($letter, 4);
					$newString = $letter . $romanLetters[$pos - 1];
				}
				$numberOfChanges++;
				$linje = str_replace($oldString, $newString, $linje);
			
			}

		}

	}
	return $linje;
}

function roman2dec ($linje) {
	# Fixing variable so it follows my convention
	$linje = strtoupper($linje);
	
	# Removing all not-roman letters
	$linje = ereg_replace("[^IVXLCDM]", "", $linje);

	print("\$linje	= $linje<br>");
	
	# Defining variables
	$romanLettersToNumbers = array("M" => 1000, "D" => 500, "C" => 100, "L" => 50, "X" => 10, "V" => 5, "I" => 1);

	$oldChunk = 1001;

	# Looping through line
	for($start = 0; $start < strlen($linje); $start++) {
		$chunk = substr($linje, $start, 1);
		
		$chunk = $romanLettersToNumbers[$chunk];
		
		if($chunk <= $oldChunk) {
			$calculation .= " + $chunk";
		} else {
			$calculation .= " + " . ($chunk - (2 * $oldChunk));
		}
		
	
		$oldChunk = $chunk;
	}
	
	# Summing it up
	eval("\$calculation = $calculation;");
	return $calculation;

}

# Implementation of the array_search function. Works only with numerical arrays.
function array_search($searchString, $array) {
	foreach ($array as $content) {
		if($content == $searchString) {
			return $pos;
		}
		$pos++;
	}
}
?>

WinBatch[edit]

;==========================================================================================================================================
; udfArabicToRoman (intArabicNumber) ; Returns a roman number string for a given arabic number 0..99999.
; udfRomanToArabic (strRomanNumber)  ; Returns an arabic number 0..99999 for a given roman number string.
;==========================================================================================================================================

;------------------------------------------------------------------------------------------------------------------------------------------
#DefineFunction udfArabicToRoman (intArabicNumber)
intArabicNumber = Min (99999, Max (0, intArabicNumber)) ; Limit range for sure.
If intArabicNumber == 0 Then Return ""
strList = ",I,II,III,IV,V,VI,VII,VIII,IX"
strList = strList : ",,X,XX,XXX,XL,L,LX,LXX,LXXX,XC"
strList = strList : ",,C,CC,CCC,CD,D,DC,DCC,DCCC,CM"
strList = strList : ",,M,MM,MMM,MF,F,FM,FMM,FMMM,MT"
strList = strList : ",,T,TT,TTT,TY,Y,YT,YTT,YTTT,TH"
arrRomanDigits = Arrayize (strList, ",") ; Special symbols appended.
Drop (strList)
strRomanNumber = ""
intI = 0
While intArabicNumber > 0
   intArabicValue = intArabicNumber mod 10
   intArabicNumber = intArabicNumber / 10
   strRomanNumber = arrRomanDigits [intArabicValue + 10 * intI] : strRomanNumber
   intI = intI + 1
EndWhile
Return strRomanNumber
;..........................................................................................................................................
; This UDF "udfArabicToRoman" returns a roman number string for a given arabic number in the range 0..99999.
; Roman numbers are: M=1000, CM=900, D=500, CD=400, C=100, XC=90, L=50, XL=40, X=10, IX=9, V=5, IV=4, I=1.
; There also exist historical roman symbols for the values 5.000, 10.000, 100.000, 1.000.000.
; But sadly there exist no applicable symbols in standard computer character set.
; As a very special alternative this function uses F=5000, T=10000, Y=50000 H=100000.
; This function works for arabic numbers in the range 0..99999.
;
; Detlev Dalitz.20010325.20090708.
;..........................................................................................................................................
#EndFunction
;------------------------------------------------------------------------------------------------------------------------------------------


;------------------------------------------------------------------------------------------------------------------------------------------
#DefineFunction udfRomanToArabic (strRomanNumber)
If strRomanNumber == "" Then Return 0  ; String is empty.
strRomanNumber = StrUpper (StrTrim (StrFixLeft (strRomanNumber, "", 20))) ; Limit string length.
strCleanStr = StrClean (strRomanNumber, " HYTFMDCLXVI", "", @TRUE, 2)
If StrCmp (strCleanStr, strRomanNumber) != 0 Then Return -1 ; String is invalid.
arrArabicDigits = Arrayize ("9,4,8,7,6,5,3,2,1", ",")
strList = "TH,MT,CM,XC,IX"
strList = strList : ",TY,MF,CD,XL,IV"
strList = strList : ",YTTT,FMMM,DCCC,LXXX,VIII"
strList = strList : ",YTT,FMM,DCC,LXX,VII"
strList = strList : ",YT,FM,DC,LX,VI"
strList = strList : ",Y,F,D,L,V"
strList = strList : ",TTT,MMM,CCC,XXX,III"
strList = strList : ",TT,MM,CC,XX,II"
strList = strList : ",T,M,C,X,I"
arrRomanDigits = Arrayize (strList, ",")
Drop (strList)
intArabicNumber = 0
intI = 0
While @TRUE
   intLenPre = StrLen (strRomanNumber)
   strRomanDigit = arrRomanDigits [intI]
   strRomanNumber = StrReplace (strRomanNumber, strRomanDigit, "")
   intLenPost = StrLen (strRomanNumber)
   If intLenPre != intLenPost
      intArabicValue = arrArabicDigits [intI / 5] * (10 ** (4 - (intI mod 5)))
      intArabicNumber = intArabicNumber + intArabicValue
   EndIf
   If !intLenPost Then Break
   intI = intI + 1
EndWhile
Return intArabicNumber
;..........................................................................................................................................
; This UDF "udfRomanToArabic" returns an integer number in the range 0..99999 (resp. -1 if argstr is invalid).
; Roman numbers are: M=1000, CM=900, D=500, CD=400, C=100, XC=90, L=50, XL=40, X=10, IX=9, V=5, IV=4, I=1.
; There also exist historical roman symbols for 5.000, 10.000, 100.000, 1.000.000.
; But sadly there exist no applicable symbols in standard computer character set.
; As a very special alternative this function uses F=5000, T=10000, Y=50000 H=100000.
; This function works for arabic numbers in the range 0..99999.
;
; Detlev Dalitz.20010325.20090708.
;..........................................................................................................................................
#EndFunction
;------------------------------------------------------------------------------------------------------------------------------------------


; Test.

While @TRUE
   ; To break the loop press "Cancel" button while in dialog Askline or in dialog Pause.
   intAskNum = AskLine ("Roman / Arabic Number Conversion", "Enter a number (should be in range 0..99999)", "")
   strRomanNumber = udfArabicToRoman (intAskNum)
   intArabicNumber = udfRomanToArabic (strRomanNumber)
   strOut = intAskNum : " = " : strRomanNumber : " = " : intArabicNumber : @LF : @LF
   strOut = strOut : "Known symbols" : @TAB : @TAB : "Special symbols" : @LF
   strOut = strOut : "M" : @TAB : "= 1000" : @TAB : @TAB : "H" : @TAB : "= 100000" : @LF
   strOut = strOut : "D" : @TAB : "= 500" : @TAB : @TAB : "Y" : @TAB : "= 50000" : @LF
   strOut = strOut : "C" : @TAB : "= 100" : @TAB : @TAB : "T" : @TAB : "= 10000" : @LF
   strOut = strOut : "L" : @TAB : "= 50" : @TAB : @TAB : "F" : @TAB : "= 5000" : @LF
   strOut = strOut : "X" : @TAB : "= 10" : @LF
   strOut = strOut : "I" : @TAB : "= 1" : @TAB : @TAB : "Range = 0..99999" : @LF
   Pause ("Number Conversion:  Arabic ==> Roman ==> Arabic", strOut)
EndWhile

:CANCEL
Exit
; This WinBatch code example was written by Detlev Dalitz.20090708.1900.CEST
;;;