BOINC@AUSTRALIA FORUM
Retired BOINC Projects => NQueens@HOME => Topic started by: Cruncher Pete on May 18, 2009, 01:31:35 PM

(http://nqueens.ing.udec.cl/img/logo/NQueensLogo1b.png) (http://www.boincstats.com/signature/team_59_project56.gif)
Project Summary
The original eight queens problem consisted of trying to find a way to place eight queens on a chessboard so that no queen would attack any other queen. An alternate way of expressing the problem is to place eight anythings on an eight by eight grid such that none of them share a common row, column, or diagonal.
It has long been known that there are 92 solutions to the problem. Of these 92, there are 12 distinct patterns. All of the 92 solutions can be transformed into one of these 12 unique patterns using rotations and reflections. If we increase the size of the chessboard beyond 8 rows/columns, we might want to find how many solutions exist for any arbitrary board size N. For example, if N = 10, then there are 724 solutions. Of these, 92 are distinct. To date, it's known that for N = 25 there are 2,207,893,435,808,352 solutions[1]. This result were obtained by two diferent sources:
* from Objectweb ProActive INRIA Team (proactive(AT)objectweb.org), Jun 11 2005 [Communicated by Alexandre Di Costanzo (Alexandre.Di_Costanzo(AT)sophia.inria.fr)]. This calculation took about 53 years of CPU time.
* been confirmed by the NTU 25Queen Project at National Taiwan University and Ming Chuan University, led by YuhPyng (Arping) Shieh, Jul 26 2005. This computation took 26613 days CPU time.
I don't know any project trying to solve the N=26 problem.
Applications
The following applications are supported:
Microsoft Windows X86 (32bit)
Linux X86 (32bit)
Linux X86_64 (64bit)
Mac OS X PowerPC
Mac OS X Intel
Connecting to NQUEENS@Home
The project's Home Page is located at: http://nqueens.ing.udec.cl/ (http://nqueens.ing.udec.cl/)
NQUEENS@Home is also listed in the various BOINC Account Managers and you can join this project through them directly.
Don't forget to join BOINC@Australia Team following your registration.
Statistics
View our Team Members List and their current score here (http://nqueens.ing.udec.cl/team_members.php?teamid=20&offset=0&sort_by=expavg_credit)
View detailed BOINCStats here (http://boincstats.com/stats/team_graph.php?pr=nqueens&id=20)