299. Bulls and Cows 自己写已ac

class Solution {public:    string getHint(string secret, string guess) {        map<char,int> mp;        if(secret.size()==0)return "";        int a=0,b=0;        string ss;        for(int i=0;i<secret.size();i++){            if(secret[i]==guess[i]){                a++;            }            else {                mp[secret[i]]++;                ss+=guess[i];            }        }        for(int i=0;i<ss.size();i++){            if(mp[ss[i]]>0){                b++;                mp[ss[i]]--;            }        }        return to_string(a)+"A"+to_string(b)+"B";    }};