Rubik's family cubes of all sizes Rubik's family cubes of all sizes The original Rubik's cube was a mechanical 3×3×3 cube puzzle invented in 1974 by the Hungarian sculptor and professor of architecture Ernő Rubik. Extensions of the Rubik's cube have been around for a long time and come in both hardware and software forms. The major extension have been the availability of cubes of larger size and the availability of the more complex cubes with marked centres. The properties of Rubik’s family cubes of any size together with some special attention to software cubes is the main focus of this article. Many properties are mathematical
Rush Hour (puzzle) has a solution is PSPACE-complete. This is proved by reducing a graph game called Nondeterministic Constraint Logic, which is known to be PSPACE-complete, to generalized Rush Hour positions. Tromp and Cilibrasi (2004) showed that "Rush Hour" is still PSPACE-complete when the cars are of size 2 only. They also conjectured that "Rush Hour" is still nontrivial when the cars are of size 1 only. Rush Hour (puzzle) Rush Hour is a sliding block puzzle invented by Nob Yoshigahara in the 1970s. It was first sold in the United States in 1996. It is now being manufactured by ThinkFun (formerly Binary