Finding 5x5 solver

TomBecker · Posted: Wed Aug 24, 2005 1:56 pm Post subject: Finding 5x5 solver

Hi all, I don't know if this is the true place to explain my question, I hope!

Does anyone know if there's a solver of a 5x5 sudoku table?
Because I'm going crazy, I started it but I can't finish it!
Could tell me some link to some 5x5 solver?

TomBecker · Posted: Wed Aug 24, 2005 6:42 pm Post subject:

Thanx anyway! Crying or Very sad

Merri · Posted: Wed Aug 24, 2005 10:47 pm Post subject:

This is a slow moving forum. And you shouldn't hurry with things. Anyways, I actually made a 5 x 5 solver out of my 3 x 3 solver, but I need to fix it a bit to make it load faster (due to some of my optimization tricks it consumes a whole lot of memory with a bigger board until I edit the code more).

gaby · Posted: Wed Aug 24, 2005 11:16 pm Post subject:

I've built mine with a mind to solving NxN puzzles, but I haven't tried it on anything other than a 3x3. I believe Pappocom's sudoku solver will take custom sized puzzles, including all odd shapes and the like.
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TomBecker · Posted: Thu Aug 25, 2005 6:45 am Post subject:

If you want to share the exe I'll test it, because I'm stopped and I don't know how can I continue to finish the 5x5.

gaby · Posted: Thu Aug 25, 2005 9:55 am Post subject:

It's PHP code, so if you can send me the puzzle I'll see if it can solve it.
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http://vanhegan.net/sudoku/

dukuso · Posted: Thu Aug 25, 2005 1:20 pm Post subject:

or just change the first line in this :
http://www.setbb.com/phpbb/viewtopic.php?t=119&mforum=sudoku
to
# define N 5

or get an executable from
http://magictour.free.fr/suexk.exe

TomBecker · Posted: Thu Aug 25, 2005 1:52 pm Post subject:

I tried but I received:
0 solutions for sudoku#1
0 solutions for sudoku#2
0 solutions for sudoku#3
0 solutions for sudoku#4
0 solutions for sudoku#5

Very Happy

dukuso · Posted: Thu Aug 25, 2005 3:14 pm Post subject:

what/where is sudoku#1,..,5 ?
it expects symbols 1,2,3,4,5,6,7,8,9,A,B,...,,P

TomBecker · Posted: Thu Aug 25, 2005 4:53 pm Post subject:

Rewind sorry I told you wrong thing, the sudoku is 25x25, sorry!

gaby · Posted: Thu Aug 25, 2005 6:19 pm Post subject:

Well, It's a bit of a beast! How many numbers did you manage to fill in?
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TomBecker · Posted: Thu Aug 25, 2005 6:43 pm Post subject:

Rerewind I'm a little bit confused Wink

the sudoku is 5x5 sorry Very Happy

xyzzy · Posted: Thu Aug 25, 2005 7:10 pm Post subject:

Can you post the problem? I've never run my solver on a 5x5, I'd be interested to see if it can solve it in a reasonable time.

rallveird · Posted: Thu Aug 25, 2005 11:21 pm Post subject:

If you want to solve a 25x25 you need to implement logic methods to start the solving. My program can solve 25x25 easy enough. You can find a lot of 25x25 puzzles on my site http://www.menneske.no/sudoku/5/eng/

But just to make you understand how difficult bruteforce a 25x25 with few startnumber is. To generate a solution on an empty 9x9 you usually need only 81 iterations (inserting random numbers, only allowing legal numbers to be inserted). Sometimes you need up to 90 iterations. Since there is 81 numbers in the grid, this is almost no backtracking.

Generating a solution for a 25x25 is a different thing. Here you can need millions of iterations. Generating a 9x9x9 (3D) you need billions of iterations. And this is if you only insert legal numbers, meaning you have to check which numbers can be inserted into a cell before inserting them, and finding the cell with least numbers to insert. If you want to brute force from the top left to the bottom right you would probably need 1000 times these numbers.

This is why you need a logic solver as a start on these big puzzles, or find the magic cells - which is tremendous help Smile

gaby · Posted: Thu Aug 25, 2005 11:30 pm Post subject:

So far, it's segfaulted my solver (but it is written in PHP... Smile

I'm working on a way to make it more efficient. Or some other way to avoid having to learn/write C...

I get as far as finding some hidden number chains before it runs out of memory.

Gaby
_________________
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http://vanhegan.net/sudoku/