Bulls and Cows (Code Breaker)

Bulls and Cows is an old code-breaking paper and pencil game, predating the similar commercially marketed board game Mastermind.

It is a guessing game in which the computer generates a random number or word and the user's objective is to try and guess this word.

The game deals with different levels of varying difficulties.
The game not only deals with number guessing but also with alphanumeric words.