Mastermind is a game where one has to guess the computer generated number with clues given by the computer for every guess. An 'o' means one of the digits is correctly guessed, but in the wrong place. A '*' means one of the digit is correctly guessed, and is in the correct place.
Examples:
Hidden number: 1234 Guess: 5678 Output:
Hidden number: 1234 Guess: 1235 Output: ***
Hidden number: 1234 Guess: 4321 Output: oooo
Hidden number: 1111 Guess: 1234 Output: *