Comments on: traveling elephpant

By: admin

admin — Thu, 02 Feb 2012 12:48:16 +0000

@Dave Edwards SplFixedArray were introduced in PHP 5.3, make sure you are running 5.3 or newer.

By: Dave Edwards

Dave Edwards — Sun, 29 Jan 2012 19:29:13 +0000

Class ‘SplFixedArray’ not found…

$nodeTrail = new SplFixedArray(count($dataset)+1);

Is there is a class missing?

Thanks

Dave

By: Andy Thompson

Andy Thompson — Sun, 04 Jul 2010 09:01:54 +0000

Ouch, that must be very frustrating.

I had another look at your algorithm, and came up with changes to my own. The speed I calculated from my own ratio is very subjective though.

Check it out in my comments on my blog article

http://andytson.com/blog/2010/05/travelling-elephpant-solutions/comment-page-1/#comment-31

By: admin

admin — Thu, 01 Jul 2010 08:52:58 +0000

After Ivo posted on twitter that some entries were calculating one location too little I got a nagging feeling and checked my code.

On line 200, where I add the final node to the completed path I actually overwrote the last location instead of adding it.

$nodeTrail[$step++] = $endNodeKey;
vs.
$nodeTrail[++$step] = $endNodeKey;

I never got my exact speed score, so I don’t know the numbers. I do know I was a little more then twice as slow as Remi’s entry which was 11s. So my speed was probably ~25 seconds or so.

By: Andy Thompson

Andy Thompson — Thu, 01 Jul 2010 06:14:13 +0000

Hi Erik,

I noticed you picked what looks like the same algorithm as mine, though mine was optimised for complexity and LOC rather than speed.

Did you find and fix the bug? How was the speed of it in the end?

Andy