Talk:15 puzzle/Archive 1

Proof,
I have a strong background in mathematics but did not understand the proof. Can someone please clarify the language? Asteron 17:59, 29 August 2006 (UTC)


 * Yes, that piece seems to be unclear, but English is not my native language, and I perhaps can't clarify this in the best way. I suggest you to follow the link on top of this Talk Page and read the last but one paragraph there. I think, it's clear enough. Cmapm 18:33, 29 August 2006 (UTC)

Parity
The parity does not change, regardless of the number of rows the empty block is moved. Every time the empty block changes rows, it creates an odd number of permutation inversions. — Preceding unsigned comment added by 134.173.58.68 (talk) 19:01, 13 November 2006 (UTC)

NP hard?
Is there a formal proof that the problem of finding the shortest solution is an NP hard problem? How is the reduction of this problem? —The preceding unsigned comment was added by 201.240.224.179 (talk) 03:33, 1 January 2007 (UTC).

Requested move

 * The following discussion is an archived debate of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section. 

The result of the debate was PAGE MOVED per unopposed request. -GTBacchus(talk) 04:15, 29 January 2007 (UTC)
 * N-puzzle → Fifteen puzzle —(Discuss)— What it's usually called in English; that there is a 3x3 form is a minor consideration. The present name could denote any puzzle with an integer parameter. —Septentrionalis PMAnderson 22:53, 22 January 2007 (UTC)

Survey
Add "* Support" or "* Oppose" or other opinion in the appropriate section followed by a brief explanation, then sign your opinion with ~
 * Support as nom. Septentrionalis PMAnderson 22:55, 22 January 2007 (UTC)

Discussion
Add any additional comments
 * The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Link to 15 puzzle download
The author of game15 has repeatedly inserted a link to his site where a version of the puzzle can be downloaded. This has become very persistent. Just wanted to check whether there was anyone who disagrees with me continuing to delete this as spam. There is already a link to a Java online version which is much better and does not require a download. The site was also originally not in English, although it has now been (badly) translated and it does not render correctly in Firefox.  Sp in   ni ng  Spark  17:49, 15 February 2009 (UTC)
 * Please keep removing it. The spam easily fails WP:EL. JackSchmidt (talk) 17:57, 15 February 2009 (UTC)

Deletion of category fads
This article has now been removed from category:fads for the second time. The category went through a deletion discussion which decided to remove all entries from the category but to allow back well-referenced ones. A terrible decision in my view, either the category should have been cleaned of the ones that don't belong or the decision made that we don't want it and delete outright. If ever there was a case of throwing out the baby with the bathwater....but whatever, getting back to this article, I cannot conceive how any fad could be more well documented than the 1880 craze for this one. If any article belongs, it is this one. I can think of several other puzzles that a good case could be made for, but I restored this one in particular because the article details the claim already and has good quality references. Perhaps the deleter was thinking that "craze" does not equal "fad", in which case I refer you to the opening words of the category page "A fad, also known as a craze..."  Sp in   ni ng  Spark  22:51, 15 October 2009 (UTC)