Roman to Integer

Roman to Integer

Given a roman numeral, convert it to an integer.

Input is guaranteed to be within the range from 1 to 3999.

mycode

class Solution:

    def romanToInt(self, s):

        """

        :type s: str

        :rtype: int

        """

        dic = {'I':1,'X':10,'C':100,'V':5,'L':50,'D':500,'M':1000}

        num_list = []

        for r in range(len(s)-1):

            if  dic[s[r]]<dic[s[r+1]]:

                num_list.append(-dic[s[r]])

            else:

                num_list.append(dic[s[r]])

        num_list.append(dic[s[-1]])

        return sum(num_list)

other

class Solution:# @param {string} s# @return {integer}def romanToInt(self, s):

roman = {'M': 1000,'D': 500 ,'C': 100,'L': 50,'X': 10,'V': 5,'I': 1}

z = 0

for i in range(0, len(s) - 1):

if roman[s[i]] < roman[s[i+1]]:

z -= roman[s[i]]

else:

z += roman[s[i]]

return z + roman[s[-1]]

def romanToInt(self, s):

"""

:type s: str

:rtype: int

"""

_dict = {'I':1,'V':5,'X':10,'L':50,'C':100,'D':500,'M':1000}

prev = 0

sum = 0

for i in s[::-1]:

curr = _dict[i]

if prev > curr:

sum -= curr

else:

sum += curr

prev = curr

return sum