Curing Instant Insanity II
Instant Insanity II is a 4 by 4 sliding tile puzzle designed by Philip Orbanes. The packaging indicates that there is a unique solution to the puzzle, up to rotations of the columns and permutations on the rows. However, a recent paper by Richmond and Young shows that there are in fact two solutions to the puzzle. This paper presents several attempts at “fixing” the puzzle to guarantee a unique solution. Of these, the only one that guaranteed a unique solution was removing a color to create a 3 by 3 puzzle.
Beeler, Robert A.; and Bentley, Amanda Justus. 2016. Curing Instant Insanity II. Mathematics Magazine. Vol.89(4). 252-261. https://doi.org/10.4169/math.mag.89.4.252 ISSN: 0025-570X