Numbers To Roman

This algorithm converts decimal numbers to roman numerals.

• C#
• VB.Net
• C
• C++
• PHP

									public static string NumbersToRoman(int num)
{
	StringBuilder roman = new StringBuilder();

	int totalM = num / 1000;
	num %= 1000;
	int totalCM = num / 900;
	num %= 900;

	int totalD = num / 500;
	num %= 500;
	int totalCD = num / 400;
	num %= 400;

	int totalC = num / 100;
	num %= 100;
	int totalXC = num / 90;
	num %= 90;

	int totalL = num / 50;
	num %= 50;
	int totalXL = num / 40;
	num %= 40;

	int totalX = num / 10;
	num %= 10;
	int totalIX = num / 9;
	num %= 9;

	int totalV = num / 5;
	num %= 5;
	int totalIV = num / 4;
	num %= 4;

	roman.Append(RepeatString("M", totalM));
	roman.Append(RepeatString("CM", totalCM));
	roman.Append(RepeatString("D", totalD));
	roman.Append(RepeatString("CD", totalCD));
	roman.Append(RepeatString("C", totalC));
	roman.Append(RepeatString("XC", totalXC));
	roman.Append(RepeatString("L", totalL));
	roman.Append(RepeatString("XL", totalXL));
	roman.Append(RepeatString("X", totalX));
	roman.Append(RepeatString("IX", totalIX));
	roman.Append(RepeatString("V", totalV));
	roman.Append(RepeatString("IV", totalIV));
	roman.Append(RepeatString("I", num));

	return roman.ToString();
}

private static string RepeatString(string s, int count)
{
	if (count < 0) return string.Empty;

	StringBuilder str = new StringBuilder(count);

	for (int i = 0; i < count; ++i)
	{
		str.Append(s);
	}

	return str.ToString();
}
								

Example

									int data = 419;
string value = NumbersToRoman(data);
								

Output

									CDXIX