4Number

4Number is an old code-breaking paper and pencil game. Also known as Cows and Bulls, is a game with numbers that may date back a century or more. It was played by two opponents. 4 Number makes it a single player type game.

At beginning the computer will select a 4-digit secret number. The digits must be all different. Then, the player tries to guess the secret number. If the matching digits are on their right positions, they are A - the "bulls", if on different positions, they are B, the "cows". Example:

Secret number: 1984
Player's try: 1249
Answer: 1A2B. (The bull is "1", the cows are "4" and "9".)

Go get the number, Lin