Guess4Digits

Guess4Digits is an ancient code-breaking puzzle game that originated in the mid-20th century. It is usually played by two or more people, or by one person and a computer. How to play:
1. Usually played by two people, one party gives a number and the other party guesses. The person who gives the number must think of a 4-digit number without repeated digits, and must not let the guesser know. The guesser can start guessing. For each number guessed, the person who gives the number must give a few A and B according to the number, where the digits before A represent the number of numbers in the correct position, and the digits before B represent the number of numbers that are correct but in the wrong position.
2. If the correct answer is 5234, and the guesser guesses 5346, it is 1A2B, where one 5 is in the correct position, recorded as 1A, and the two numbers 3 and 4 are correct, but the position is not correct, so it is recorded as 2B, which is 1A2B in total.
3. The person who guesses next continues to guess according to the number of A and B given by the questioner until he guesses correctly (i.e. 4A0B).