This project is my solution to a puzzle I heard about on YouTube, implemented as a shell pipeline. Problem ------- A warden sets up a 8x8 chess board with coins heads or tails up how ever he likes. He hides a key under one of the squares. 2 prisoners can collaborate ahead of time, but the warden can listen to their strategy before he sets up the board. The first prisoner sees where the key is and may flip one coin of his choice to communicate the location to the second prisoner. The second prisoner must then figure out where the key is. As described by Grant Sanderson (3blue1brown) to Matt Parker (standupmaths): Prisoner 1 walks in, 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. This is the website Matt mentioned with a full breakdown of the solution and interactive boards you can play with. http://datagenetics.com/blog/december... My solution ----------- - warden.sh - Generates a chessboard with one coin on each sqaure, randomly heads up or down, and picks a location for the key. - prisoner1.py - Reads the board and flips one coin. Accepts the option flag "-x" to eXplain how it is choosing which coin to flip. - prisoner2.py - Reads the board. Accepts the option flag "-x" to eXplain how it is reading the board. Run --- $ ./warden.sh | ./prisoner1.py | ./prisoner2.py To better understand how the prisoners read the board: $ ./warden.sh | ./prisoner1.py | ./prisoner2.py -x To better understand how prisoner1 chooses which coin to flip: $ ./warden.sh | ./prisoner1.py -x | ./prisoner2.py