Come to guess

The Guess Number (also known as Bulls and Cows) is a puzzle game that started in the UK in the mid-20th century. This game rule is simple, but it can test people's rigor and patience.
     At the beginning of each game, a four-digit number is automatically generated and the four digits are not repeated. Each time you guess a number, you will get a few A B, where the number in front of A indicates the number of correctly positioned numbers, and the number in front of B indicates the number of numbers that are correct and not in the right position. If the correct answer is 5234, and if you enter 5346, it is 1A2B, where there is a 5 position right, recorded as 1A, and the 3 and 4 numbers are correct, and the position is not correct, so it is recorded as 2B, together it is 1A2B. Then continue to guess according to the recorded number A and B until you guess (ie 4A0B).
   Let's challenge it~