13. 罗马数字转整数

够简洁

class Solution {
public:
    int romanToInt(string s) {
        vector<int> backet(150);
        backet['I'] = 1;
        backet['V'] = 5;
        backet['X'] = 10;
        backet['L'] = 50;
        backet['C'] = 100;
        backet['D'] = 500;
        backet['M'] = 1000;
        int ans = 0;
        for(int i = 0; i < s.size(); i++) {
            if(i != s.size() - 1 && backet[s[i]] < backet[s[i + 1]]){
                ans -= backet[s[i]];
            }
            else ans += backet[s[i]];
        }
        return ans;
    }
};