|Number||B & C|
Use the helper table to eliminate the digits on impossible positions
Bulls and Cows is a logic game to guess numbers. The numbers have to be with four digits and the digits must be all different. The game is played by two players and they take turns to try to guess their opponent's number. The answering player responds with the number of matchng digits. If they are in their right positions, they are "bulls"; if in different positions, they are "cows".
If the player's number is 7059
And the opponent asks how many matches are there in 7890
The answer is 1 "bull" and 2 "cows".