Solution implementation by Cory Leigh Rahman
Prisoner 1 walks in to a room, sees a chessboard where each square has a coin on top, flipped either to heads or tails. The warden places the key under one of the squares, which prisoner 1 sees. Before he leaves, he must turn over one and only one coin. Prisoner 2 then walks in and is supposed to be able to figure out which squares the key is in just by looking at the arrangement of coins. The Prisoners can coordinate a plan ahead of time. What's the plan?
- Website: Impossible Chessboard Escape Puzzle
- PDF: Impossible Chessboard Escape Puzzle - CLR.pdf
- Jupyter Notebook: Impossible Chessboard Escape Puzzle - CLR.ipynb
- Introduction video & walk-through: The almost impossible chessboard puzzle by Stand-up Maths
- Further discussion video: The impossible chessboard puzzle by 3Blue1Brown
- Full breakdown website with interactive examples: Impossible Escape? by DataGenetics