13.Roman to Integer (Map)

Given a roman numeral, convert it to an integer.
Input is guaranteed to be within the range from 1 to 3999.

class Solution {

public:

    int romanToInt(string s) {

        int values[] = {1000, 500, 100, 50, 10, 5, 1 };

        char numerals[] = {'M', 'D', 'C', 'L', 'X', 'V', 'I' };

        int i = 0, j = 0, result = 0;

        while(i < s.length()){

            if(s[i] != numerals[j]){

                j++;

                continue;

            }



            if(i+1<s.length() && j-1>=0 && s[i+1] == numerals[j-1]){

                result += values[j-1]-values[j];

                i+=2;

            }

            else if(i+1<s.length() && j-2>=0 && s[i+1] == numerals[j-2]){

                result += values[j-2]-values[j];

                i+=2;

            }

            else{

                result += values[j];

                i++;

            }

        }

        return result;

    }

};