I recently became interested in how we can programmatically solve the 15 puzzle. The 15 puzzle is a sliding puzzle that consists of a 4 x 4 board of tiles numbered from 1 to 15, with one empty space. The tiles are shuffled and the goal is to slide the tiles around until they are in order, i.e. the numbered tiles will run from 1 to 15 starting from the top left corner from left to right and top to bottom, with the empty space at the bottom right corner.