Comments on: Rubik’s Cube Cracked http://blog.drscottfranklin.net/2007/08/11/rubiks-cube-cracked/ Ramblings of a Christian Mathematician and Bioinformaticist Wed, 07 Jan 2009 16:34:39 +0000 http://wordpress.org/?v=2.7 hourly 1 By: Donna http://blog.drscottfranklin.net/2007/08/11/rubiks-cube-cracked/comment-page-1/#comment-44447 Donna Mon, 20 Aug 2007 20:45:49 +0000 http://blog.drscottfranklin.net/2007/08/11/rubiks-cube-cracked/#comment-44447 You know, Scott, I remember when I was smarter than you (simply becase I am older)... now I read your blog and say... um, huh? :) You know, Scott, I remember when I was smarter than you (simply becase I am older)… now I read your blog and say… um, huh? :)

]]> By: Stephen Uitti http://blog.drscottfranklin.net/2007/08/11/rubiks-cube-cracked/comment-page-1/#comment-44167 Stephen Uitti Fri, 17 Aug 2007 16:19:06 +0000 http://blog.drscottfranklin.net/2007/08/11/rubiks-cube-cracked/#comment-44167 I've written computer game solver programs for other perfect information games. 8 queens, a solitair card game, etc. One can often tell the computer how to reduce the cominations that need to be checked. The 8 queens problem can be solved by checking all 8^8'th positions (16,777,216), which used to be a big deal. But there are ways to eliminate huge parts of the problem, and all solutions can be generated in under a millisecond. Sometimes there are ways to stochastically eliminate likely dead ends and find very good solutions quickly. So, this one solitar card game i've worked on typically has something like 4^70 (10^42) possible solutions, but a computer checking less than 10^9 solutions can get one of the optimal solutions at least 999 out of 1000 times, taking a few minutes at most. The big deal recently, has been the solving of checkers, creating an unbeatable opponent. All moves are book moves. I remember hearing about the project in the late 80's. It's been 30 years. I’ve written computer game solver programs for other perfect information games. 8 queens, a solitair card game, etc. One can often tell the computer how to reduce the cominations that need to be checked. The 8 queens problem can be solved by checking all 8^8′th positions (16,777,216), which used to be a big deal. But there are ways to eliminate huge parts of the problem, and all solutions can be generated in under a millisecond.

Sometimes there are ways to stochastically eliminate likely dead ends and find very good solutions quickly. So, this one solitar card game i’ve worked on typically has something like 4^70 (10^42) possible solutions, but a computer checking less than 10^9 solutions can get one of the optimal solutions at least 999 out of 1000 times, taking a few minutes at most.

The big deal recently, has been the solving of checkers, creating an unbeatable opponent. All moves are book moves. I remember hearing about the project in the late 80’s. It’s been 30 years.

]]>