013罗马数字转整数.py

# -*- coding:utf-8 -*-
__author__ = 'ShawDa'


class Solution:
    def romanToInt(self, s):
        """
        :type s: str
        :rtype: int
        """
        nums = {'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 nums[s[i]] < nums[s[i+1]]:
                res -= nums[s[i]]
            else:
                res += nums[s[i]]
        return res