Roman To Int

LeetCode Problem

# https://leetcode.com/problems/roman-to-integer/submissions/879687255/
class Solution:
    def romanToInt(self, s: str) -> int:
        ans = 0
        mp = {"I": 1, "V": 5, "X": 10, "L": 50, "C": 100, "D": 500, "M": 1000}
        for i in range(0, len(s) - 1):
            if mp[s[i]] < mp[s[i + 1]]:
                ans -= mp[s[i]]
            else:
                ans += mp[s[i]]

        # the trick is that the last letter is always added bcs it has nothing to compare to in front of it.
        return ans + mp[s[-1]]


def intToRoman(num):
    # convert this int to string
    # 58 = LVIII L = 50, V= 5, III = 3
    ans = ""
    roman = [
        (1000, "M"),
        (900, "CM"),
        (500, "D"),
        (400, "CD"),
        (100, "C"),
        (90, "XC"),
        (50, "L"),
        (40, "XL"),
        (10, "X"),
        (9, "IX"),
        (5, "V"),
        (4, "IV"),
        (1, "I"),
    ]
    for val, symbol in roman:
        while num >= val:
            ans += symbol
            num -= val
    return ans


def main():
    print(intToRoman(58))


main()