299. Bulls and Cows

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

Python

from collections import Counter


class Solution:
    def getHint(self, secret: str, guess: str) -> str:
        counts = Counter(secret)

        bulls, cows = 0, 0
        for i, num in enumerate(guess):
            if num == secret[i]:
                bulls += 1
                cows -= 1 if counts[num] <= 0 else 0
            else:
                cows += 1 if counts[num] > 0 else 0
            counts[num] -= 1
        return "{}A{}B".format(bulls, cows)