dailysudoku.com

shea89 · Joined: 22 Apr 2012 Posts: 3

Hi guys,

I'm making a sudoku solver which can only use techniques and not brute force/backtracking, I have a number of techniques implemented in my program but I'm kind of stuck on what technique to use next.

I have a sample of 10 random hard puzzles and at the moment I'm completely solving 6 of them could someone have a look at my partially completed puzzle (possible candidates included) and maybe tell me the next technique to code.

puzzle is here -> http://i43.tinypic.com/zugnlh.png

This would be a great help thanks.

Marty R. · Posted: Sun Apr 22, 2012 6:45 pm Post subject:

I transcribed the grid which might be easier for those who have to squint.

arkietech

Marty R.

shea89 · Joined: 22 Apr 2012 Posts: 3

Thanks so much, it was pointed out to me that row 8 also has a naked quad in it so now I've now coded naked quads and naked triples I'm now solving 9/10 puzzles from my sample pool, the last puzzle is this one http://i44.tinypic.com/2ibkqqq.png

could you please tell me the technique needed to complete his puzzle?

Also you can click on the image to make it bigger if it seems too small

Thanks,
Shea.

Marty R. · Posted: Mon Apr 23, 2012 3:38 pm Post subject:

Look at the 4s in row 8.

Luke451 · Posted: Tue Apr 24, 2012 1:37 am Post subject:

What, shea89, don't trust those answers over these?

DonM · Joined: 15 Sep 2009 Posts: 51

shea89 · Joined: 22 Apr 2012 Posts: 3

Hi guys thanks for your answers I'm currently solving my sample pool of hard puzzles now, some more testing needed but hopefully its a complete solver.

As for posting on multiple sites I needed an answer pretty quick and didn't know how active the forums are so posted on this and two others.

The project I'm undertaking doesn't require me to have an advanced understanding of sudoku to successfully make a solver and I don't pretend that I'm an advanced sudoku solver so thought I'd seek the expertise of the people on these forums.

Thanks again,
Shea