Based on ideas developed by Herbert Kociemba, and independently used by Richard Korf, I wrote an optimal cube solver. This is supposed to be a practical implementation of "God's Algorithm" for Rubik's Cube. Although a very small fraction of positions may require months of searching, most can be solved in a day or so, and many require much less time than that.
I originally used (in 1997) a 200MHz Pentium Pro processor, configured with 128Mb of RAM, (but I've upgraded since then).
For random positions, it seems to average about 2.5 hours for a complete search through 17 face turns, 31 hours for a complete search through 18 face turns on my hardware. However, this seems to vary a lot depending upon the position. Also, I haven't tried many random positions. I haven't tried any random positions for the quarter turn metric yet. Let's face it, I'm not so interested in random positions; I'm more interested in symmetric positions and pretty patterns.
For another approach to God's Algorithm for Rubik's cube, see reference .
|Download optimal solver (21K gzip'd tar file)|
Enjoy the program. Please let me know about any interesting discoveries you make.
 A. Fiat, S. Moses, A. Shamir, I. Shimshoni and G. Tardos,
Planning and Learning in Permutation Groups,
Proceedings of the 30th A.C.M. Foundations of Computer Science
(FOCS) 1989, pp. 274-279.
 Herbert Kociemba's Cube Explorer. The ideas he developed for his searching algorithm are those upon which I based my program.
 Press release about Richard Korf's optimal cube solver. His program also uses similar ideas as Kociemba's.
 Cube-lovers message where I describe my searching algorithm.
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Updated October 28, 2006.