[TDD워크샵] practical session | ② RomanNumber Converter

Problem. Roman Number Converter

Given a Roman number as a string (eg "XX") determine

its integer value (eg 20).

You cannot write numerals like IM for 999.

Wikipedia states "Modern Roman numerals are written by

expressing each digit separately starting with the

leftmost digit and skipping any digit with a value of zero."

Examples:

"I" -> 1    | "X" -> 10    | "C" -> 100    | "M" -> 1000 

"II" -> 2   | "XX" -> 20   | "CC" -> 200   | "MM" -> 2000 

"III" -> 3  | "XXX" -> 30  | "CCC" -> 300  | "MMM" -> 3000 

"IV" -> 4   | "XL" -> 40   | "CD" -> 400   | "MMMM" -> 4000 

"V" -> 5    | "L" -> 50    | "D" -> 500    | 

"VI" -> 6   | "LX" -> 60   | "DC" -> 600   | 

"VII" -> 7  | "LXX" -> 70  | "DCC" -> 700  | 

"VIII" -> 8 | "LXXX" -> 80 | "DCCC" -> 800 | 

"IX" -> 9   | "XC" -> 90   | "CM" -> 900   | 

"MCMXC" -> 1990 ("M" -> 1000 + "CM" -> 900 + "XC" -> 90)

"MMVIII" -> 2008 ("MM" -> 2000 + "VIII" -> 8)

"XCIX" -> 99 ("XC" -> 90 + "IX" -> 9)

"XLVII" -> 47 ("XL" -> 40 + "VII" -> 7)