10-07-2005 14:32									#31
	Increase Your PM Length

Indeed, guess and verify *is* a logical method of proving a possibility exists.

	10-07-2005 14:52									#32
	Enter the AD-FREE zone

Could someone post a situation where you had to use the "first guess, the verify" to continiue the game?

	10-07-2005 14:55									#33
	Support Apolyton, buy Alpha Centauri

Well unless someone has a half finished sudoku they are willing to post I'd say no.

	10-07-2005 15:01									#34
	Support Apolyton buy from Amazon

But maybe someone remembers my request when they're playing a new sudoku game and gets to that point

	10-07-2005 15:22									#35
	Inflate your Upload Space

Not using guesses, then I doubt I'd ever have a situation like that. Plus, I'm too lazy to do the basic coding required to get the stupid boxes to line up.

	12-07-2005 02:03									#36
	Inflate your Upload Space

Just copy mine

	11-09-2005 00:08									#37
	Increase Your PM Length

I went crazy yesterday, and bought the Independent's first book of Super Sodoku. It's a 16x16 grid, with 0-9 and A-F to put into the squares. And I haven't even finished the first one yet.
Mainly because I've been here, or playing games.

	11-09-2005 05:58									#38
	Tired of ads?

Priorities.

	11-09-2005 11:59									#39
	Support Apolyton, buy Call to Power 2

quote: Originally posted by Adagio Could someone post a situation where you had to use the "first guess, the verify" to continiue the game?

Strictly speaking, you never have to guess unless the final solution is not unique.

	11-09-2005 14:09									#40
	Enter the AD-FREE zone

quote: Originally posted by DrSpike Well I'm not sure what the distinction between the guess and working it out is. Say there are a few possibilities left, and you put in a 'guess' and follow that 'guess' to it's logical conclusion, to find that there is no solution with your initial choice. That's one quite reasonable way of proceeding and eliminating possibilities.

	11-09-2005 22:43									#41
	Full PM-box? Change here!

Yes, but you have to spend ages removing all the wrong answers that you've written in.

	12-09-2005 10:15									#42
	Support Apolyton, buy Civilization 2

I am still interested in developing an algorithm that solves Sudoku. Maybe some time Real Soon.

	12-09-2005 17:04									#43
	Avatar Enlargement: We've got the solution

quote: Originally posted by Dauphin Not sure why it became such a massive phenomemon just now, I've been doing them for quite a while (8-9 months or whenever it was The Times started doing them) and its only in the last couple that its become the jeux du jour.

It's since a guy called Wayne Gould developed a program to generate them ad libitum.
He sold it to different papers.
Easier and cheaper to generate than classical crosswords.

	12-09-2005 21:21									#44
	Support Apolyton, pre-order Civilization IV

the Wapo now carries this Sudoko thing, so i sometimes do it on the metro after ive finished the crossword. I can do the easy ones, and almost all of the medium, but have difficulty with the hard. I prefer to do it pretty "ad hoc" POTM was doing one, and I saw here writing out some huge chart of possibilities.

	12-09-2005 21:35									#45
	Inflate your Upload Space

I haven't done any real hard ones yet, I've only tried those from timesonline (the diffecult ones from the site)

Does anyone know where to find some hard puzzles?

	12-09-2005 21:56									#46
	Support Apolyton, buy Civilization 2

Google?

Try typing hard (or difficult) Sudoku, and see what Sergei Brings you.

	12-09-2005 22:02									#47
	Support Apolyton or Terrorists Win

Sudoku.com iirc has a great puzzle generator - shareware, iirc again.

	12-09-2005 22:38									#48
	Suffering from ads?

Google sounds like a scary place


I'll try that puzzle generator, thx

	12-09-2005 22:50									#49
	Increase the size of your Attachments

quote: originally posted by Urban Ranger I am still interested in developing an algorithm that solves Sudoku. Maybe some time Real Soon.

I once programmed an evolutionary strategy to do the work. With the excessive amount of computational power nowadays, even such wasteful strategies are going to do the trick quite fast.
I guess a GA would have been better, but I was too lazy to think about CrossOver operators.

The fitness was the amount of violated constraints and the goal was to minimize them. The mutation was to exchange 2 or 3 positions in one of the smaller 9x9 grids.

	13-09-2005 01:20									#50
	Avatar Enlargement: We've got the solution

I like the Times 'killer' sudoku that they started a couple of weeks ago. More fun than the standard sudoku.

Same rules, except the grid is additionally split by dotted lines. Numbers in squares enclosed within a dotted line add up to the total written on the dotted line. Also, you don't start with any numbers already in place (unless there is a single square enclosed within a dotted line, in which case it de facto tells you what the number is).

	13-09-2005 09:40									#51
	Support Apolyton buy from Amazon

quote: Originally posted by Atahualpa quote: originally posted by Urban Ranger I am still interested in developing an algorithm that solves Sudoku. Maybe some time Real Soon. I once programmed an evolutionary strategy to do the work. With the excessive amount of computational power nowadays, even such wasteful strategies are going to do the trick quite fast.

Geek

	13-09-2005 16:14									#52
	Increase Your PM Length

Dolphin, I notice today that the Grauniad have got something called Kakuro. Trouble is, their explanation of the rules wasn't great. Maybe if I google it.

	13-09-2005 16:46									#53
	Increase Your PM Length

quote: Originally posted by Atahualpa The fitness was the amount of violated constraints and the goal was to minimize them. The mutation was to exchange 2 or 3 positions in one of the smaller 9x9 grids.

Im not an expert in algorithms so maybe I missed something.
Wouldn't it be possible to get stuck with that algorithm?
Its possible that 2 or 3 position changing is not going to improve the solution anymore, specially if you consider only one 3x3 box at a time...
Of course for easier puzzles it will work...

	13-09-2005 17:55									#54
	Increase Your PM Length

Yes that's a problem and that's why I thought a crossover or an ES with recombination operator would do better, but it was a quick work and I didn't put that much effort. Plus I could solve most puzzles with several tries. The easier ones even with a 1+1 ES, the tougher ones required a bigger population.