private static void AddDigitRangeToString(ref Int32 input, ValueDigitPair high, ValueDigitPair middle,
ValueDigitPair low, StringBuilder sb)
{
AddDigitToString(ref input, high.Value - low.Value, String.Concat(low.Digit, high.Digit), sb);
AddDigitToString(ref input, middle.Value, middle.Digit, sb);
AddDigitToString(ref input, middle.Value - low.Value, String.Concat(low.Digit, middle.Digit), sb);
while (input >= low.Value)
{
AddDigitToString(ref input, low.Value, low.Digit, sb);
}
}
public static String Convert(Int32 input)
{
var sb = new StringBuilder();
var thousand = new ValueDigitPair(1000, "M");
var fiveHundred = new ValueDigitPair(500, "D");
var oneHundred = new ValueDigitPair(100, "C");
var fifty = new ValueDigitPair(50, "L");
var ten = new ValueDigitPair(10, "X");
var five = new ValueDigitPair(5, "V");
var one = new ValueDigitPair(1, "I");
while (input >= 1000)
{
AddDigitToString(ref input, thousand.Value, thousand.Digit, sb);
}
AddDigitRangeToString(ref input, thousand, fiveHundred, oneHundred, sb);
AddDigitRangeToString(ref input, oneHundred, fifty, ten, sb);
AddDigitRangeToString(ref input, ten, five, one, sb);
return(sb.ToString());
}