13.roman-to-integer.py

#
# @lc app=leetcode id=13 lang=python3
#
# [13] Roman to Integer
#

# @lc code=start
class Solution:
    def romanToInt(self, s: str) -> int:
        m = {
            'I': 1,
            'V': 5,
            'X': 10,
            'L': 50,
            'C': 100,
            'D': 500,
            'M': 1000
        }
        
        ans = 0
        
        for i in range(len(s)):
            if i < len(s) - 1 and m[s[i]] < m[s[i+1]]:
                ans -= m[s[i]]
            else:
                ans += m[s[i]]
        
        return ans
# @lc code=end