Pattern based generator (VB6 code available)

Lunatic · Last edited by Lunatic on Mon Apr 20, 2009 4:02 pm; edited 10 times in total

For anyone interested, i've been updating my pattern based sudoku generator recently and is now downloadable, just click here. Visual Basic source code is available too.
Since there's no Help file, i will provide some information here...

This is the interface:

How to generate sudokus:
-Choose a base pattern (using "Next" or "Previous" buttons, or create a new one by toggling the cells on/off with the mousecursor. The red cells are those where the givens are to be generated.
-Choose the required modifications, there are only two sorts of modifications possible. The first one, Limited to "Very Hard" will limit the generated sudokus to the "Very Hard" level. With the other option you can make the generator try to expand the base pattern with 1, 2 or 3 extra givens which will only occur if the base pattern has multiple solutions making attempts to find a unique solution. By default, this option is set to "Don't expand, seek sequential". This default option will seek for the first unique sudoku from a maximum of 250 sequential attempts based on the first randomly generated givens. If no unique sudoku is found within 250 attempts, the givens are randomly regenerated, and so on.
[EDIT 1 = April 12th 2008]
- Added the possibility to change the number of sequential attempts
- Added the posibility to request Minimal check for both generator and uniqueness test, this means that all clues are needed to have a unique solution
[END EDIT 1]
[EDIT 5 = October 6th 2008]
- Added the possibility to generate with randomly choosen patterns from those allready available
[END EDIT 5]

The whole generator is based on my pseudo-dancing links brute force solver written in Visual Basic. See topic "DANCING LINKS and VISUAL BASIC"

The patterns have some restrictions...
-a minimum of 20 givens is required
-more than one empty row within the same band is not allowed
-more than one empty column in the same stack is not allowed
-more then four empty boxes are not allowed

About the randomly generated givens...
-the given cells are adressed in random order (by using a randomly re-ordered GivenMap-array)
-each given cell will recieve the available candidates in random order (by using a randomly re-ordered multiple CandidateMap-array)

About the levels...
1) Very Easy - Sudokus requiring only hidden singles
2) Easy - Sudokus also requiring naked singles
3) Medium - Sudokus also requiring box-line reductions and/or pointing pairs
4) Hard - Sudokus also requiring naked subsets
5) Very hard - Sudokus also requiring hidden subsets

Generated sudokus not answering to these levels are called "others".
[EDIT 2 = April 12th 2008]
- switched hidden and naked singles from level.
The basic solve techniques "Crosshatching" and "Slicing & dicing" normally spots hidden singles. Naked singles are easier to spot if you use pencilmarks. Since pencilmarks are normally needed for higher levels, i changed the order for the easy levels.
[END EDIT 2]

[EDIT 3 = April 27th 2008]
Output files:
The following output file types are available:

1) MPQ Sudoku file type
Very Easy: Sudoku_Very_Easy.sds
Easy: Sudoku_Easy.sds
Medium: Sudoku_Medium.sds
Hard: Sudoku_Hard.sds
Very Hard: Sudoku_Very_Hard.sds
Others: Sudoku_Others.sds

Each file can hold multiple sudokus, format is built up this way:
There's no file-header, and each sudoku is saved in a 166 bytes long record. The first 81 bytes are reserved for the sudoku to be solved, and are saved in binary format. The following 81 bytes are holding the solution, also in binary format. The last 4 bytes of each sudoku record are reserved for keeping the best solving time for that sudoku, 2 bytes (in fact, an integer value) for the minutes, and another integer value for the seconds.
To import them with MPQ Sudoku, see the help file topic MPQ Sudoku – File Check and Import (only for advanced users)

2) Simple Sudoku file type
Very Easy: Very_Easy_0001.ss, Very_Easy_0002.ss, ...
Easy: Easy_0001.ss, Easy_0002.ss, ...
Medium: Medium_0001.ss, Medium_0002.ss, ...
Hard: Hard_0001.ss, Hard_0002.ss, ...
Very Hard: Very_Hard_0001.ss, Very_Hard_0002.ss, ...
Others: Others_0001.ss, Others_0002.ss, ...
Each file holds one sudoku, format is built up this way:
There's no file-header, and each sudoku is saved in text-format like this example:

gsf · Posted: Thu Apr 03, 2008 6:59 pm Post subject: Re: Pattern based generator

Lunatic · Posted: Thu Apr 03, 2008 7:07 pm Post subject: Re: Pattern based generator

gsf · Posted: Thu Apr 03, 2008 8:00 pm Post subject: Re: Pattern based generator

Lunatic · Posted: Fri Apr 11, 2008 4:39 pm Post subject: Re: Pattern based generator

gsf · Posted: Fri Apr 11, 2008 5:56 pm Post subject: Re: Pattern based generator

Lunatic · Posted: Sat Apr 12, 2008 9:55 am Post subject:

Allmost there......

Downloaded SudokuExplainer.jar and put it in folder C:\SUDPAT

My generated sudokus are in the same folder in file GAMEXXXX.txt where XXXX = the number of the game (currently 0026)

I use following command (with arguments):
java -Xrs -Xmx500m -cp C:\SUDPAT\SudokuExplainer.jar diuf.sudoku.test.serate -f%g/%r/%p/%d -iC:\SUDPAT\GAME0026.txt -oC:\SUDPAT\RATE0026.txt

Works fine !

Now, to submit puzzles, they must have following properties:

valid (obvious)
same pattern (obvious)
minimal (have to implement this check in my generator)
not isomorphic to any previous puzzle in the current game
So, I must keep track of all posted puzzles in the current game, and find out if my puzzles are not isomorphic to them.
Why ?
If my puzzle is isomorphic to any previous posted one, should i not expect the same ratings ? In other words, if i get other/higher ratings, is my puzzle then not by definition non-isomorphic ?
_________________
Marc
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tarek · Posted: Sat Apr 12, 2008 11:01 am Post subject:

JPF · Posted: Sat Apr 12, 2008 1:10 pm Post subject:

Right, see here.
The current SE 1.2.1 still has this bug.

JPF

gsf · Posted: Sat Apr 12, 2008 1:55 pm Post subject:

Lunatic · Posted: Sat Apr 12, 2008 9:04 pm Post subject:

Lunatic · Posted: Sun Apr 27, 2008 7:20 pm Post subject:

April 27th 2008:

Update now available with following new features:

Added a pattern browser under the new "Pick button".
Included a selection list to choose from different output file-types.
Fixed some bugs...

See [EDIT 3] section at first post of this topic for more details

Please remove any previous version before installing the new one !!!

Regards,
Lunatic.
_________________
Marc
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Lunatic · Posted: Mon Oct 06, 2008 5:56 pm Post subject:

October 6th 2008:

Update now available with following new feature:

- Added the option to generate sudokus using randomly choosen patterns from those allready available.

See [EDIT 5] section at first post

Please remove any previous version before installing the new one !!!

Regards,
Lunatic.
_________________
Marc
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