LeetCode-13-Roman-to-Integer 无聊模拟，递归

跟上个题差不多，特判一下IX和IV这种情况就行了

class Solution(object):
    def romanToInt(self, s):
        """
        :type s: str
        :rtype: int
        """
        romanMap={}
        romanMap['I']=1
        romanMap['V']=5
        romanMap['X']=10
        romanMap['L']=50
        romanMap['C']=100
        romanMap['D']=500
        romanMap['M']=1000
        
        Len=len(s)
        if Len==0:
            return 0
        if Len==1:
            return romanMap[s[0]]
        if romanMap[s[0]]<romanMap[s[1]]:
            return self.romanToInt(s[2:])+romanMap[s[1]]-romanMap[s[0]]
        return self.romanToInt(s[1:])+romanMap[s[0]]