Project done on Hyperskill It has three difficulty levels: easy, medium and hard. To play, type "start player1 player2". Each player can be user or a difficulty level. The first player plays first and uses X, the second one uses O. Type in coordinates as in a xy plane, ranging from 1 to 3.
The easy difficulty level makes random moves. The medium difficulty level tries to win when it can in the next move, or blocks the user when he/she would win in the next move. The hard difficulty level makes use of minimax to guess the best outcome from all possible moves.