Given two strings of equal length, secret_code and guess_code, both consisting of digits, compute a hint string in the format "xAyB" where x is the number of positions where secret_code and guess_code have the same digit (bulls), and y is the number of digits in guess_code that exist in secret_code but are not in the same position (cows). Each digit in secret_code and guess_code can only be counted once for bulls or cows. Return the hint string.
Example 1
Input: secret_code=1234, guess_code=4321
Output: 0A4B
Explanation: No bulls, all digits are cows.
Example 2
Input: secret_code=5555, guess_code=5566
Output: 2A0B
Explanation: Two bulls (positions 0 and 1), no cows.
Example 3
Input: secret_code=9876, guess_code=9876
Output: 4A0B
Explanation: All bulls, no cows.
Constraints
Case 1
Input: secret_code='2468', guess_code='8642'
Expected: '0A4B'
Case 2
Input: secret_code='0000', guess_code='1000'
Expected: '3A0B'
Case 3
Input: secret_code='1230', guess_code='3210'
Expected: '2A2B'
Case 4
Input: secret_code='1112', guess_code='2111'
Expected: '1A2B'
Case 5
Input: secret_code='7890', guess_code='0987'
Expected: '0A4B'