|
Rubik's Cubers
Shoutbox - 11 comments
You must be logged in to post comments.
unbread says:
My average time is about 1:20, and my fastest is about a minute.
Umm... what is with the ruff stuff around the edges?http://www.angelfire.com/un/questionableq/bkrub.gif
posted Apr 18
Joe says:
could you get a different group image?
something like thishttp://www.cs.plattsburgh.edu/~salvador/figs/rubik.gif
posted Mar 26
Pages: 1 (11 total comments)
Joe says:
Cooperman and Kunkle were able to accomplish this new record through two primary techniques: They used 7 terabytes of distributed disk as an extension to RAM, in order to hold some large tables and developed a new, %u201Cfaster faster%u201D way of computing moves, and even whole groups of moves, by using mathematical group theory.
Cooperman and Kunkle put all of the configurations of a Rubik's cube in a family of sets of configurations (called a family of cosets in mathematical group theory). They then looked at the result of applying a single move to all of the configurations of a coset at once. They simulated this on a computer at a rate of 100,000,000 times per second, using a new technique in mathematical group theory.
In May 1997, U.C.L.A. computer science Professor Richard Korf announced that he had found the first optimal solutions to Rubik's Cube. His research showed that the median optimal solution was 18 moves, and he believed any cube could be solved in no more than 20 moves. However, he was unable to prove this, and no one has ever been able to prove that it could be solved in less than 27 moves.
%u201CKorf had written a program that spends a long time to find optimal solutions for single states of the Rubik's cube,%u201D says Kunkle. %u201COur program first does a large pre-computation and then it very quickly - in about a second - finds a solution in 26 moves or less for any state of Rubik's cube.
source
posted Jun 4