The Game
Mastermind (https://en.wikipedia.org/wiki/Mastermind_(board_game)) is an old game. The plastic version that was ubiquitous in every house with children was invented in 1970. I got a board around 1980 as a Christmas gift and solving the game puzzle in BASIC language was one of the first programs that I created around 1984.
The game board contains holes in several rows in four columns. There are plastic pins of six different colors that can be inserted into the holes. Each pin has one color. They are usually red, green, blue, yellow, black, and white. There is a special row that is hidden from one of the players (the guesser).
To play the game, one of the players (hider) has to select four pins from a set of pins. The selected pins should have different colors. The pins are placed in the hidden row one by one, each into a position.
The guesser tries to find out what colors are in which position guessing. Each guess takes place selecting four pins and placing them in a row. The hider...