class Solution{
    public: 
        int romanToInt(string s){
            unordered_map<char,int> convert = {{'I',1},{'V',5},{'X',10},{'L',50},{'C',100},{'D',500},{'M',1000}};
            int result = 0;
            for(int i=0;i<s.size();++i){
                int curr = convert[s[i]];
                int next = ((i+1) < s.size())? convert[s[i+1]] : 0;
                if(curr<next){
                    result-=curr;
                }else{
                    result+=curr;
                }
            }
            return result;
        }
};