Roman-To-Integer.py

#! /usr/bin/env python
#! -*- coding=utf-8 -*-
# Date: 2019-11-04
# Author: Bryce
#Python Solution 1:
class Solution(object):
    def romanToInt(self, s):
        """
        :type s: str
        :rtype: int
        """
        words = {}
        res = 0
        i = 0
        words['I'] = 1; words['V'] = 5;
        words['X'] = 10; words['L'] = 50; 
        words['C'] = 100; words['D'] = 500;
        words['M'] = 1000;
        
        while i < len(s):
            if i + 1 < len(s) and words[s[i+1]] > words[s[i]]:
                res += words[s[i+1]] - words[s[i]]
                i +=2
            else:
                res += words[s[i]]
                i += 1
        return res

    #Python Solution 2:
    class Solution(object):
    def romanToInt(self, s):
        """
        :type s: str
        :rtype: int
        """
        words = {'I':1, 'V':5, 'X':10, 'L':50, 'C':100, 'D':500, 'M':1000}
        res = 0
        for i in range(len(s)):
            if i < len(s)-1 and words[s[i+1]] > words[s[i]]:
                res -= words[s[i]]
            else:
                res += words[s[i]]
        return res
    
    if __name__ == " __main__ ":
        a = "III"
        print ( Solution().romanToInt (a) )