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No Magic In A Knight's Tour
morgothan writes "As reported in an article on Math World the solution, or rather lack of solution has been found to the over one hundred fifty year old math problem of how many numbers of magic tours a knight can make on a standard 8x8 chessboard. It turn out that there exist one hundred forty distinct semimagic tours, but no magic tour. The solution came after 61.40 CPU-days, corresponding to 138.25 days of computation at 1 GHz, the project was completed on August 5, 2003 in which every possible enumeration was tried out. The author of the software that finally solved the problem has also put up a webpage in which he further explains the problem and his method of solving it." Thanks to Mig for pointing out a great background page on Chessbase.com.
Maybe if the Knight REALLY wanted to take a Magic Tour he'd consult a Wizard instead of a Computer...
No wonder he didnt only got a Semimagic tour, damn you Travelocity! Damn you to hell!
This is my sig. Its pathetic.
The solution came after 61.40 CPU-days, corresponding to 138.25 days of computation at 1 GHz
I bet the horse was tired after hopping around so much.
The unofficial
Now we're going to examine how many routes there are through all the bars in Amsterdam, and see if there are any "magic" routes that will let us complete the circuit without falling drunk in a bed of tulips.
Sheesh, evil *and* a jerk. -- Jade
> The webpage mentions that the program is windows based and doesn't save state. That means that all of those CPU hours came in a row (at idle priority even). Bash MS all you want, but Windows isn't as unstable and problematic as all of your anti-MS zealots would like to believe.
61.40 CPU-days spread between 10 people's computers, and you think that indicates enough uptime to brag about? Puh-leeze.
Sheesh, evil *and* a jerk. -- Jade
uptime is nothing to brag about, unless you're talking about your penis.
Given: an 8x8 chess board, a black knight piece, a Cray supercomputer
1. Execute brutechess.exe
2. Therefore, there are no magic knight's tours.
Magic knight's not touring? What am I gonna do with these damn tickets...
So even if it doesn't have practical applications it's still important.
:-)
:-/
Why?
Oh yes, we don't have to spend some of the brightest minds have to work on a useless problem anymore. But I'm sure they'll find another one.
Nope, but they got through about six coconuts.
"Nah. A result is a result no matter what methods were used to produce it. No cheating."
I spy an Nvidia engineer!
The solution came after 61.40 CPU-days, corresponding to 138.25 days of computation at 1 GHz
Yeah, and I came to work in 12.34 horsepower-hours, corresponding to 666.13 hours of driving at 5K RPM. I mean, damn, I understand when my mom utters movie-level technobabble, but this?
I just wrote a quick demonstration program to find them...
"How to Do Nothing," kids activities, back in print!
Put my mind at rest.. I've been worrying about this for years.
Oh please. Next you'll want to know the exact DRAM configuration. Was it DDR? How big was the L2? Was the data set swapped out to a 7200rpm hard disk or a 10k rpm disk?
Good grief. It's just an estimate. It's not the exact compute time that's interesting. It still tells me the interesting bits-- that it was a complexity that an ordinary PC could do in a reasonable time frame, not the sort of thing a gigantic cluster chewed on for 100 years.
The ones they use at the Library of Congress of course!
Is this a /. first? Well I won't let it happen. Hey, screw the magical knight tour, how about solving 9x9 Go?
-Libertarian secular transhumanist
Sir Paul McCartney did make a Magical Mystery Tour
I for one would find you hitting your hand with a hammer much more interesting then watching you work it out on pen and paper. ;)
I like my women how I like my sugar.. granulated.