Since the author seems interested in the maximum number of moves required to solve the puzzle, a similar puzzle called Subway Shuffle far outdoes Rush Hour. For example, puzzle 100 involves 9 pieces on a 10-spot grid, but requires (as far as is known, maybe the solution isn't optimal?) 589 steps to solve. https://www.cs.brandeis.edu/~storer/JimPuzzles/ZPAGES/zzzSub...
Does anyone know if a version of this is available for Android? I've had no luck searching.
It also seems like something that would be great as part of Simon Tatham's puzzle collection: https://www.chiark.greenend.org.uk/~sgtatham/puzzles/ / https://play.google.com/store/apps/details?id=name.boyle.chr...
It turns out that Rush Hour becomes much harder if we shrink the cars from size 2x1 to size 1x1, while maintaining their direction to be either horizontal or vertical [1]. While the hardest 6x6 Rush Hour puzzle takes 51 moves, the hardest Unit Rush Hour puzzle takes a whopping 732 moves [2].
Great article, very impressive to solve the entire game, rather than just individual puzzles.
PS: Good chance that if you're reading these comments that you will appreciate this video by 2swap, visualising solutions to Rush Hour in 3D: https://youtu.be/YGLNyHd2w10?si=fGFqzEbmV3utbA0O
Fun article.
The Rush Hour puzzle is quite fun when viewed as a planning problem. In standard PDDL the model becomes very messy. I like the extensions proposed in https://arxiv.org/abs/2412.06312v1 that makes the model intuitive.
Thanks for the article, perfect timing. Was stuck on a secret Santa gift for the brother in law. Rush hour is perfect!