public static ArabicNumeral ConvertRomanNumeral(string romanNumeral)
{
if (String.IsNullOrEmpty(romanNumeral))
{
throw new ArgumentException("The Roman Numeral to convert cannot be null or empty.", nameof(romanNumeral));
}
ArabicNumeral arabicNumeral = null;
if (ARABIC_NUMERALS_MAP.Keys.Contains(romanNumeral))
{
arabicNumeral = ARABIC_NUMERALS_MAP[romanNumeral];
}
return(arabicNumeral);
}
public static string ConvertRomanNumber(string romanNumber)
{
if (String.IsNullOrEmpty(romanNumber))
{
throw new ArgumentException("The Roman Numeral to convert cannot be null or empty.", nameof(romanNumber));
}
int?arabicNumber = 0;
for (int i = 0; i < romanNumber.Length && arabicNumber.HasValue; i++)
{
ArabicNumeral arabicNumeral = ConvertRomanNumeral(romanNumber[i].ToString());
if (arabicNumeral != null)
{
ArabicNumeral nextArabicNumeral = null;
if (i + 1 < romanNumber.Length)
{
nextArabicNumeral = ConvertRomanNumeral(romanNumber[i + 1].ToString());
}
if ((nextArabicNumeral != null) && (nextArabicNumeral.IntegerValue > arabicNumeral.IntegerValue))
{
if (((nextArabicNumeral.IntegerValue != arabicNumeral.IntegerValue * 5) && (nextArabicNumeral.IntegerValue != arabicNumeral.IntegerValue * 10)) ||
(arabicNumeral.IntegerValue == 5) || (arabicNumeral.IntegerValue == 50) || (arabicNumeral.IntegerValue == 500))
{
arabicNumber = null;
}
else
{
arabicNumber -= arabicNumeral.IntegerValue;
}
}
else
{
arabicNumber += arabicNumeral.IntegerValue;
}
}
}
return(arabicNumber.HasValue ? arabicNumber.ToString() : String.Empty);
}