Roman To Numbers

This algorithm converts roman numerals to decimal numbers.

									private enum RomanDigit
{
	I = 1,
	V = 5,
	X = 10,
	L = 50,
	C = 100,
	D = 500,
	M = 1000
}

public static int RomanToNumbers(string roman)
{
	roman = roman.ToUpper().Trim();
	if (roman == "N") return 0;

	int ptr = 0;
	ArrayList values = new ArrayList();
	int maxDigit = 1000;
	while (ptr < roman.Length)
	{
		char numeral = roman[ptr];
		int digit = (int)Enum.Parse(typeof(RomanDigit), numeral.ToString());

		int nextDigit = 0;
		if (ptr < roman.Length - 1)
		{
			char nextNumeral = roman[ptr + 1];
			nextDigit = (int)Enum.Parse(typeof(RomanDigit), nextNumeral.ToString());

			if (nextDigit > digit)
			{
				maxDigit = digit - 1;
				digit = nextDigit - digit;
				ptr++;
			}
		}

		values.Add(digit);
		ptr++;
	}

	int total = 0;
	foreach (int digit in values)
		total += digit;

	return total;
}

Example

									string data = "CDXIX";
int value = RomanToNumbers(data);

Roman To Numbers

Example

Output