Solution: Bulls and Cows

Statement

You are playing a number guessing game called “Bulls and Cows” with a friend.

You write down a secret number, and your friend tries to guess it. After each guess, you provide a hint based on the following:

• Bulls: The number of digits that are in the correct position in the guess.

• Cows: The number of digits that are in both the secret and the guess but in different positions. (These are non-bull digits that could become bulls if rearranged.)

Your task is to return a hint for the guess, formatted as “xAyB”, where:

• x is the number of bulls.

• y is the number of cows.

Note: Both the secret number and the guess may contain duplicate digits.

Constraints:

• $1 <=$ secret.length, guess.length ...