[Nicholas Carlini] programmed a C implementation of two-player Tic Tac Toe, and he did it in a single call to printf(). The arguments for that single function call get mind-bendingly complex ...

Tic-tac-toe (or “Noughts and Crosses”) is a game ... then draws the standard 3×3 grid and makes its first move. The human then draws their move and uses a remote control to tell the robot ...