LeetCode 299. Bulls and Cows

class Solution {
public:
int digit[10];

string getHint(string secret, string guess) {

    int a = 0, b = 0;
    for (int i = 0;i < secret.length();i++)
    {
        if(secret[i]==guess[i])
        {
            a++;
            continue;
        }
        digit[secret[i] - '0']++;
    }
   
    
    for (int i = 0;i < guess.length();i++)
    {
        if(secret[i]==guess[i])
            continue;
        
        int number = guess[i] - '0';
        if(digit[number]==0)
            continue;
       
        b++;
        digit[number]--;
        
    }

    string str = "";
    str +=  to_string(a);
    str += 'A';
    str += to_string(b);
    str += 'B';
    return str;

}
};