Leetcode 299. Bulls and Cows

文章作者：Tyan
博客：noahsnail.com  |  CSDN  |  简书

1. Description

2. Solution

• Version 1

class Solution {
public:
    string getHint(string secret, string guess) {
        int bull = 0;
        int cow = 0;
        int length = secret.length();
        for(int i = 0; i < length; i++) {
            if(secret[i] == guess[i]) {
                bull++;
            }
        }
        sort(secret.begin(), secret.end());
        sort(guess.begin(), guess.end());
        int indexSecret = 0;
        int indexGuess = 0;
        while(indexSecret != length && indexGuess != length) {
            if(secret[indexSecret] == guess[indexGuess]) {
                indexSecret++;
                indexGuess++;
                cow++;
            }
            else if(secret[indexSecret] > guess[indexGuess]){
                indexGuess++;
            }
            else {
                indexSecret++;
            }
        }
        cow -= bull;
        return to_string(bull) + "A" + to_string(cow) + "B";
    }
};

• Version 2

  class Solution {
  public:
      string getHint(string secret, string guess) {
          int bull = 0;
          int cow = 0;
          int length = secret.length();
          map<char, int> secretMap;
          map<char, int> guessMap;
          for(int i = 0; i < length; i++) {
              if(secret[i] == guess[i]) {
                  bull++;
              }
              else {
                  if(secretMap[guess[i]] > 0) {
                      cow++;
                      secretMap[guess[i]]--;
                  }
                  else {
                      guessMap[guess[i]]++;
                  }
                  if(guessMap[secret[i]] > 0) {
                      cow++;
                      guessMap[secret[i]]--;
                  }
                  else {
                      secretMap[secret[i]]++;
                  }
              }
          }
          return to_string(bull) + "A" + to_string(cow) + "B";
      }
  };

Reference

1. https://leetcode.com/problems/bulls-and-cows/description/