SudokuSolver Forum

Hi,

JSudoku is a Sudoku solver, helper and generator written in Java. It works fine under Windows, Mac OS X and should work equally fine under Linux.

The main focus in on Killer Sudoku, but it also support vanilla Sudoku and a bunch of other variants : Sudoku X (diagonal), JigSaw, Gatai (Samurai, Clueless), Even/Odd & the like, (non) consecutive, Greater/Less than... which may be all combined.

See : http://jcbonsai.free.fr/sudoku/?cat=7

Here is a screen shot, better than 1000 words ?



I wrote a User guide

It’s free and for private use only.

Comments and suggestions are welcome.

I've just released a new version 1.3b1

Added Finned X-Wing, Swordfish, Jellyfish… solvers. Will also detect the sashimi case.
Added Skyscraper solver. It’s a particular case of a turbot fish which is easier to spot than other turbots, so I made it a separate solver. Note: it’s also a sashimi X-Wing.
Added Sue de Coq solver. It searches for “Two-Sector Disjoint Subsets”.
Added ALS-XZ solver. It searches for two Almost Locked Set with a restricted common (X) and an outer common (Z). It will remove Z from buddies of all cells with Z in the two ALS’s. Note: it will also catch WXYZ-Wings.
Added Uniqueness Test solvers for Unique Rectangles (UR) type 1 to 6 and Hidden Unique Rectangle. I will also search for Avoidable Rectangles type 1 to 3 (equivalent to UR with some solved cells)
Adapted Complex naked pair solver to detect naked pairs between ALS in UR type 3 and a sum cage. This is used only when Uniqueness Test 3 is enabled.
Adapted Conflicting combination solver to detect conflicts with Unique Rectangles. A cage covering all UR cells with extra possibilities cannot have both “deadly” possibilities. A cage which is a buddy of all UR cells with extra possibilities cannot have all extra possibilities. This is used only when Uniqueness Test 3 is enabled.
Added Cages Grouping solver. It checks combinations of two adjacent or overlapping cages together. This is last in the list since it does not give the logical reasons for the eliminations. So you’ll have to findout the logic yourself. Nevertheless, it could help spotting areas of interset, where eliminations can be made.
...

_________________
Jean-Christophe
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes.

Many very nice improvements! Thanks a lot JC.

Some nit-picking

1) Under Windows I am unable to run 1.2b1 and 1.3b1 simultaneously on the same PC.
Would make it easier to set the sequence of solver techniques in 1.3b1 similar to to the sequence I use in 1.2b1.
EDIT:
VERY BAD: The first start of 1.3b1 seems to have ruined my settings of the sequence of solver techniques in 1.2b1!

2) Separate solvers for 2-String Kite and Remote Pairs would be nice.
AFAIK 2-String Kites are more common than Skyscrapers.

3) Row and column headers as we have discussed per PM; Please!

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Quis custodiet ipsos custodes?

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Wow, it can do the Assassin 50 V2!


However, before you all get too excited, here are the stats and the HUGE solver log (including a finned jellyfish found near the start!) in TT. It's clearly way off the scale of anything that can be reasonably posted on any forum without ending up on the "Unsolvables" list.


And now for the solver log, in all its glory...:

Thanks for the update, Jean-Christophe! I'm sure it will provide us all with hours of endless fun, as I'm sure the upcoming SudokuSolver version will, too. I am constantly amazed that you and Richard are obviously able to invest so much time and energy into your software. Keep up the great work, both of you!

_________________
Cheers,
Mike

JC,

More info regarding the changes you have made to the solver from 1.2b1 to 1.3b1 would be very much appreciated.
I am currently testing a beta version of my Samurai generator and decided to switch from using 1.2b1 as the logical solver to using 1.3b1, and there seems to be some changes. The main problem is that I cannot switch forth and back between the two versions because doing so completely ruins my setting of the sequence of solver techniques, and resequencing it takes a good 10 minutes.
The ability to move a block of solving techniques would be great.

Here the JSudoku Solver logs from 1.2b1 and 1.3b1 for the generated Samurai listed at the end:

1.2b1
193 Naked Singles
65 Hidden Singles
10 Intersections

1.3b1
182 Naked Singles
76 Hidden Singles
3 Intersections

000204000709060000003009586000042300032005070090300201901520000020090000000000000
001907050000005001200600400000009108780002046069400070000530000000000000000000000
000070000000000000000310000078000005200850090000007081000008000000600000000020000
390000000005060000800500000009020004041090008600150020050001490002000005000000000
000097408000130500000000000802000000306050000000043809201300000000016030000000000

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Quis custodiet ipsos custodes?

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Mike Wow A50V2, at last my tryfurcation can be consigned to history.

Borge I have run both versions simultaneously, in fact it was the first thing I tried, as I thought JC might have resequenced the order of grid visits for the Clueless Explosion..

Some way off handling Ronin though, one more Finned Fish and an ALS, but needs those inter-grid chains. Recursively solved with 27 guesses.

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I have 81 brain cells left, I think.

1) Reason: The set of solvers is different, so they're reset to defaults whenever you switch between 1.2 & 1.3. Sorry, I can't really change this. At least, you get a warning message in 1.3 which you do not get in older versions.

2) Turbot fish will catch 2-String Kites (as well as skyscrapers). 2-String Kite is maybe more common, but harder to spot for a human beeing, so I made it a separate solver. I'll put Remote pairs in my list.

3) I know, but didn't find the time to add this in 1.3b1




1.2 stops searching at the first Intersection found, so it made some less efficient moves before hitting the key one(s) which unlocks the puzzle.
Whereas 1.3 will continue to search for Intersections until it finds a pattern revealing some single(s). If no single was revealed, it will then choose the most efficient one found, where "efficiency" is based on the number of candidates removed and number of cells changed.
Naked pairs, triplets... use the same principle.
In the future, I may adopt this principle for other solvers which currently stop searching at the first pattern found.

_________________
Jean-Christophe
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes.

Proud to announce JSudoku could also solve Ruud's Assassin 68V3. Altough I personally consider the new "Cages Grouping" solver some kind of limited T&E since it doesn't give the reasoning for the eliminations. All it says is "these two cages together -> ..."

Couldn't solve these monsters (not really a surprise)
8) July 27th 2007: Para's Special Killer-X 4V2
9) Aug 1st 2007: Mhparker's Assassin61XV3

Nor this one (which could be solvable some day)
14) January 11, 2008: A85 (original version)


I didn't add support for Samurai X yet, so JSudoku does not make use the diagonals. A workaround is to specify the 5 * 4 diagonals as extra groups. I did try so but JSudoku coun't solve it. Note: Recursively Solve reported 21 guesses for me, not 27...

_________________
Jean-Christophe
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes.

Strangely, the stats for the A50V2 that I posted above show "16 Cages Grouping", but I can't find the words "these two cages together" (or similar) anywhere in the provided solver log...

_________________
Cheers,
Mike

I solved this problem. Works when I unzip and install JSudoku.exe on the HD and start it from there, instead of starting it off the zip file, i.e. from within the zip program.


I assume that you under Windows save the solver preferences in the registry; cannot find a separate file with them. I haven’t used a Macintosh in years, but I know for sure that UNIX/LINUX does not have a registry; for many years I was a UNIX admin. If you under Mac OS and/or UNIX save the solver preferences in a separate file, please start doing this under Windows also. AND use a separate file for each version, or allow a single file to contain the settings for several versions.

IMNSHO the registry is not good for anything except:
1) Continuously making your PC running slower and slower and ....
2) Giving Malware & Co an easy time.
3) Spying on the user.
4) Making forensic easy.
With the right tools it is unbelievable what kind of information you can find in the registry. Every time you put something into a USB port (especially USB sticks) information is stored in the registry. So if you are not allowed to put a USB stick into your PC at work and then does it; finding it out (even years later) is a piece of cake!

UNIX is a good example of why KISS (Keep It Stupid Simple) is a good principle.
Windows (read Vista) is a brilliant demonstration of why KIUC (Keep It Unnecessary Complicated) in not such a good idea.


AFAIK I have not seen this message


Is your anwer that you sometime in the future will add a separate solver for Remote Pairs, but NOT for 2-String Kite?


I did read your blog BEFORE posting, but wanted some more information, which you now have provided. Thanks a lot


Whenever I start JSudoku it always starts generating a puzzle. Any way of preventing this?

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The preferences are saved when the program quits. If you run two versions at the same time, changing the preferences for one version will not alter the preferences of the other running version.

I do not program under Windows but under Java Runtime Environment. So I use the Java Preferences. I really don't know (nor mind) where and how this is actually stored.

I'll have to check this.

Yes
BTW Was too tired this morning. It should read "so I made skyscraper a separate solver".

Not in the current version. I could add an option in the furure (stored in the Preferences )

_________________
Jean-Christophe
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes.