Bulls and Cows LeetCode solution in C++

1
class Solution {
2
 public:
3
  string getHint(string secret, string guess) {
4
    int bulls = 0;
5
    vector<int> v1(10, 0);
6
    vector<int> v2(10, 0);
7
    for (int i = 0; i < secret.size(); ++i) {
8
      if (secret[i] == guess[i]) {
9
        ++bulls;
10
      } else {
11
        ++v1[secret[i] - '0'];
12
        ++v2[guess[i] - '0'];
13
      }
14
    }
15
    int cows = 0;
16
    for (int i = 0; i < 10; ++i) {
17
      cows += min(v1[i], v2[i]);
18
    }
19
    return to_string(bulls) + "A" + to_string(cows) + "B";
20
  }
21
};