Comments on: N-Queens in a Tweet

By: Famous Anonumous

Famous Anonumous — Wed, 29 Sep 2010 09:14:02 +0000

Nice article. Another usefull site about the N queen puzzle is this which describes varius fast algorithms and has source codes and executables for download.

By: mkeblx

mkeblx — Thu, 12 Nov 2009 21:54:36 +0000

Taking @Jon and improving on that line of thought wouldn’t it make the most sense to use the best language for the job? Surely there is a language that has this algorithm built into it at a core level, and not in a supplementary standard library.

Perhaps:
NQueens n(8) //NQueens is a fundamental data type
print(n)

21 characters is all. Haskell is verbose in comparison.

By: helge

helge — Thu, 23 Jul 2009 11:16:38 +0000

http://www.pastie.org/556242
268 chars.. perfectly suited for two tweets!

The bonus on this one is that it solves the 8-queens problem in about 0.001s!
I might try to push this under 200 in the weekend.

By: Jon Harrop

Jon Harrop — Thu, 23 Jul 2009 10:16:02 +0000

That’s because you’re using a non-mainstream language. If you use something decent like Java then its standard library actually provides an n-queens object factory generator that you can instantiate and just call. The code is still longer but it requires much less thought to write and unit test…

Cheers,
Jon.

By: Ryan Ingram

Ryan Ingram — Wed, 22 Jul 2009 22:25:26 +0000

You can golf a couple of characters off by replacing

(\x y->x:show y)
with
((.show).(:))

By: Anonymous Rex

Anonymous Rex — Wed, 22 Jul 2009 18:11:58 +0000

Have you seen the Perl Golf solution at http://masak.org/carl/w/index.php/Perl:Golf ?

It’s a very thorough example of golfing.

By: Paul Butler

Paul Butler — Sun, 28 Jun 2009 00:14:03 +0000

Thanks for the comparison, Rajesh.

Unfortunately WordPress has a bad habit of dropping characters from PHP code in comments, rather than just displaying them as characters.

Edit: never mind, I hadn’t seen your second comment in the moderation queue. Need to fix my comment settings.

By: Rajesh Kumar

Rajesh Kumar — Sat, 27 Jun 2009 23:41:50 +0000

Okay, wordpress ate up my solution. Here’s the link:
http://files.getdropbox.com/u/396326/nqueens.txt

By: Rajesh Kumar

Rajesh Kumar — Sat, 27 Jun 2009 23:40:12 +0000

I got 303 chars in PHP:

$n=$argv[1];$s=range(1,$n);while($i$k)$r[$i]=$k+$b[$i];return $r;}

and it only spits out ONE solution, not all! PHP is VERBOSE!