13.Roman to Integer (Map)

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;
    }
};