Bulls and Cows
|Last edited: 2024-5-14
ID
299
Data Type
Hashmap / Hashset
Difficulty
Medium
Tags
URL
https://leetcode.com/problems/bulls-and-cows/
Completed Date
May 14, 2024
Preference
You are playing the Bulls and Cows game with your friend.
You write down a secret number and ask your friend to guess what the number is. When your friend makes a guess, you provide a hint with the following info:
  • The number of "bulls", which are digits in the guess that are in the correct position.
  • The number of "cows", which are digits in the guess that are in your secret number but are located in the wrong position. Specifically, the non-bull digits in the guess that could be rearranged such that they become bulls.
Given the secret number secret and your friend's guess guess, return the hint for your friend's guess.
The hint should be formatted as "xAyB", where x is the number of bulls and y is the number of cows. Note that both secret and guess may contain duplicate digits.
Example 1:
Example 2:
Constraints:
  • 1 <= secret.length, guess.length <= 1000
  • secret.length == guess.length
  • secret and guess consist of digits only.
 

题解

这个题比较简单，逐位找，如果一样就A++，不一样要记录下，我一开始想的是只记录一个，结果发现不知道最后有几个数，只能检测全部是不同位的，如果有同位就检测不到了，例如 0011 和 1100