This is a solitaire version of the popular two-person Master Mind game.
Puzzle and Goal
An unsolved puzzle consists of a set of guesses at a mastermind solution with the corresponding clues.
The goal is to find the solution number that satisfies the clues.
The solved grid must satisfy the following conditions:
Black numbers indicate numbers in the right place.
White numbers indicate numbers in the solution but in the wrong place.
Codebreaker; Meisterhirn; Safe; Safecode