class Solution {

 public:

     string getHint(string secret, string guess) {

         int cntA = , cntB = ;

         int sn[] = {}, gn[] = {};

         for(string::size_type i = ; i < secret.size(); ++i){

             if(secret[i] == guess[i]) cntA++;

             sn[secret[i]-'']++;

             gn[guess[i]-'']++;

         }

         for(int i = ; i< ; ++i){

             cntB += min(sn[i],gn[i]);

         }

         char s[];

         sprintf(s, "%dA%dB",cntA,cntB-cntA);

         return string(s);

     }

 };