299. Bulls and Cows - cocoder39/coco39_LC GitHub Wiki

string getHint(string secret, string guess) {
        int bull = 0;
        int cow = 0;
        int len = secret.length();
        const int sz = 10;
        vector<int> cnt(sz);
        
        for (int i = 0; i < len; i++) {
            if (secret[i] == guess[i])  bull++;
            else    cnt[secret[i] - '0']++;
        }
        
        for (int i = 0; i < len; i++) {
            if (secret[i] == guess[i])  continue;
            if (cnt[guess[i] - '0']) {
                cow++;
                cnt[guess[i] - '0']--;
            }
        }
        
        return to_string(bull) + "A" + to_string(cow) + "B";
     }