Bulls and Cows

299. Bulls and Cows

Solution

1. cow is related with the number of correct characters. If bull has used up the corrected characters, a misplaced correct character is not considered as cow.

2. Count the number of bull.

3. Count the sum of matched correct characters.

4. cow = matched - bull

   def getHint(self, secret, guess):
    """
    :type secret: str
    :type guess: str
    :rtype: str
    """
    bull, cow = 0, 0
    dic = collections.Counter(secret)
   
    for x, y in zip(secret, guess):
        if x == y:
            bull += 1
    cow = sum((dic & collections.Counter(guess)).values()) - bull
    return '{}A{}B'.format(bull, cow)