AJ ([info]splag) wrote,
@ 2006-09-26 15:15:00
Previous Entry  Add to memories!  Tell a Friend!  Next Entry
Sudoku Slam

Bill and I have been slaving over this site for months, and we're finally (slowly) releasing it to the public. We think it's (by far) the best Sudoku web site out there... for once, it's more fun to solve Sudokus on the computer than it is with pencil and paper!

We wrote everything from scratch (puzzle generator, hint machine, solver UI, etc.), in javascript, c, perl, and python. It was a lot of fun but also lots of work.

So, if you (a) like Sudokus or (b) like any of my previous LJ posts, please link to this site yourself! Or send it to some friends. I mean, and send it to some friends.

My plea is desperate and shameless: that much javascript should never go to waste.

Of course, site feedback/comments are definitely welcome. Huzzah!

(Post a new comment)


[info]cychan
2006-09-27 07:04 am UTC (link)
Two thumbs enthusiastically up! I'm not very good at Sudoku, so I don't have a whole lot of experience solving them, but I felt I significantly improved over the course of the puzzles I just played in the last few hours. I recommend using the Smart Hints as a tool to learn the techniques used to solve these things.

In the end, I think used the number highlighting as a gigantic crutch... I'd definitely be a lot worse without it. Maybe that's the point?

Did you guys already know all the techniques used to solve Sudoku puzzles, or did you figure that out in the process of writing your website? Also, how do you determine the difficulty of the puzzles? Do you generate a puzzle, solve it, then base the difficulty on the hardest technique required during the mechanical solve process?

(Reply to this) (Thread)

[info]splag
2006-09-27 04:34 pm UTC (link)
Yeah we find highlighting cruicial after a while as well. It's funny because when you go back to paper and pencil, you realize how tedious the highlighting is when you have to do it yourself.

We knew many techniques but found others by surfing the web and looking at some other (offline) sudoku clients.

Difficulty -- we generate a crapload of puzzles using a very fast generator I wrote in C. Then we use the hint program to try to solve them. It can solve about 2/3. (The C program uses a contraint solver and DFS to generate puzzles. All the puzzles have unique solutions, but not all have "logically derivable" unique solutions that don't invole some form of backtracking.)

You're right: the difficulty is based on a combination of the hardest move and the number of just hard moves.

(Reply to this) (Parent)(Thread)

[info]cychan
2006-09-27 10:17 pm UTC (link)
My proudest achievement of the week: http://www.sudokuslam.com/?bookmark=250
Bodyslam in 2:18, 0 hints, 0 undos.

(Reply to this) (Parent)(Thread)

[info]splag
2006-09-29 04:22 am UTC (link)
Hey, unfortunately it turns out there was a bug in the puzzle ranking code and many puzzles were marked bodyslam that weren't supposed to be. We're reranking all the puzzles now.. so you'll have to repeate this feat on a new puzzle to truly feel proud :). Sorry about the bug!

(Reply to this) (Parent)(Thread)

[info]cychan
2006-09-29 04:31 am UTC (link)
Yeah, it was totally too easy. After that puzzle with the two X-Wings, I realized that there must have been some mistake.

(Reply to this) (Parent)

[info]rwclark
2006-09-27 04:29 pm UTC (link)
I don't really get Sudoku. Can you explain it?

(Reply to this) (Thread)

[info]splag
2006-09-27 04:43 pm UTC (link)
You have a 9x9 grid, composed of 9 3x3 grids.

The grid starts out with some squares already filled with numbers 1-9. The goal is to fill out the rest of the squares, one number per square, such that each row, column, and 3x3 grid has each number 1-9 exactly once.

That's all there is to it. A crucial thing is that there's only one correct answer per starting grid, so you should never have to guess -- there's a reason each number has to go in its spot.

If you want, go to sudokuslam.com, start up a puzzle, and just keep clicking on "smart hint" and doing what it says. It should show you some basics of how to play.

(Reply to this) (Parent)(Thread)

[info]catherinedokis
2008-07-16 04:04 am UTC (link)
If there is only one solution, it should be obvious that if you use *all* the information in the puzzle, then the value at each position is forced.

(Reply to this) (Parent)

[info]johnxorz
2006-09-29 03:21 pm UTC (link)
Awesome site! The interface is great!

One thing that wasn't clear to me was how much work the solver was doing in slam mode. Sometimes it filled in many obvious moves, often completing the entire board towards the end of the game. However, it didn't always take all the fully constrained moves -- there were times when I had only one possibility for a row, column, or box, but the solver didn't fill it in.

(Reply to this) (Thread)

[info]splag
2006-09-29 03:24 pm UTC (link)
Wow, really? That's deifnitely not supposed to happen. Could you bookpark a puzzle (Tools->Save/share this puzzle) in which a square isn't getting autofilled and send it to me? That would be great.

Also thanks for the compliments!

AJ

(Reply to this) (Parent)(Thread)

[info]johnxorz
2006-09-29 03:40 pm UTC (link)
It happens in just about every puzzle. Try puzzle #303. Shouldn't column 3, row 7 be assigned 1, and column 8, row 5 be assigned 9?

(Reply to this) (Parent)(Thread)

[info]splag
2006-09-29 06:45 pm UTC (link)
Ah I see. Nope, autofill only fills in a number in a square if the number is the only possible candidate for the box (explicitly). It does not fill it in if there's some implicit reason why the number has to go there (e.g. only place in that 3x3 box that this particular number could go).

In general, you're in charge of the implicit stuff.

If you use candidate highlighting a lot, then the implicit things become more obvious. But many people don't use it at all, so an aggressive autofill like that might appear confusing (and remove some of the challenge).

In the future, we might have a "variable-power" autofill where you can set how smart it is yourself ... some people could have it do nothing, and others could have it automatically do all but the hardest moves. Could be cool :).

(Reply to this) (Parent)

[info]johnxorz
2006-09-29 03:41 pm UTC (link)
Also, the smart hint system is great. That's how I learned how to play. ;)

(Reply to this) (Parent)
Sudoku Slam not working
(Anonymous)
2007-08-02 02:32 pm UTC (link)
Hi. I have enjoyed playing Sudoku Slam for many months now, but over the last few days, I can't get it to load. It comes up briefly, but then "grays out" and I don't get the message about wanting the 60 second tour, etc. Nothing can be selected, and the gray does not go away. Any ideas? klstock@hotmail.com

(Reply to this)

[deleted]
(Anonymous)
2007-10-30 04:54 am UTC (link)
Sorry

(Reply to this)


[info]jaderikus
2008-07-21 11:07 pm UTC (link)
Awesome!

(Reply to this)

Hello
(Anonymous)
2008-08-19 05:26 am UTC (link)
I'm new here, just wanted to say hello and introduce myself.

(Reply to this)

Create an Account
Forgot your login or password?
Login w/ OpenID
English • Español • Deutsch • Русский…