Sliding Puzzle with Periodic Boundary Conditions
A sliding puzzle with 16 pieces is placed on a 4×4 grid with periodic boundary conditions. Unlike the 15 puzzle (see Related Links below), all grid cells are filled with a puzzle piece. Although there is no empty cell in the puzzle, the rows and the columns of the puzzle can slide because of the periodic boundary conditions.
A variant of this Demonstration for Windows Phone is available at Apps from fbrechte.