13. Roman to Integer.py

class Solution:
    def romanToInt(self, s: str) -> int:
        roman={
            "I":1,
            "V":5,
            "X":10,
            "L":50,
            "C":100,
            "D":500,
            "M":1000
        }
        
        res=0
        
        for i in range(len(s)):
            if(i+1<len(s) and roman[s[i]]<roman[s[i+1]]):
                res-=roman[s[i]]
            else:
                res+=roman[s[i]]
            
        return res