I'm eventually going to move everything from here to http://sudokuban.sourceforge.net.

24 Jan 2006

If you're looking for SudokuBan on the Linux Format 76 coverdisc, it's called sudoku-sensei-1.0.tar.gz. The name is different, but the software is otherwise identical to SudokuBan 1.0.

15 Dec 2005

Sudoku Sensei has now been renamed to SudokuBan. A project called Sudoku Sensei already existed, and is much better suited to the name.

Keep an eye out for LXF 76.

For a description of Sudoku, see the Wikipedia article.

A copy of the GNU General Public License is included with the program. You can also view it at the GNU website.

1. Download and install the dependencies.
2. Download and extract the latest version of the SudokuBan tarball.
3. Run sudokuban.py.

The program starts up with a blank 3x3 puzzle. You can enter numbers by selecting a square and typing a number, or by right-clicking on a square and selecting from the menu. The Presets option is selected by default; this means that any numbers you enter to begin with will be part of the starting configuration of the puzzle. Turn this off when you've entered all of the given numbers.

To create a random puzzle, click the New button. Hover the mouse over an option to see a description of what it does.

To load an existing puzzle, select Open from the File menu. The puzzles directory distributed with SudokuBan contains some sample puzzles of different sizes, roughly ordered by difficulty.

If you get stuck on a puzzle, try some of the hints:

• Highlight - when you select a number, all rows, columns and regions that contains that number are coloured so that you can easily identify where else it fits.
• Restrict - while this is selected, you will only be able to place a number in a square if it is valid to do so. Right-click on a square to see which numbers are still available for it.
• Solve - not so much a hint as a last resort when you get fed up with a puzzle.

• Python version 2.3 or later. Download
• GTK+, preferably version 2.6 or later. Download
• PyGTK, preferably version 2.6 or later. Download

It should work on any platforms for which the above dependencies are available (essentially Linux and other UNIX-likes, and Windows). It has been successfully run on Debian, Ubuntu, SUSE and Windows XP.

Download sudokuban-1.0.tar.gz, extract it, and follow the instructions.

To get the latest development version (be prepared to wait):

    bzr branch http://rightside.fissure.org/sudoku/sudokuban.bzr

This program was originally written in search of a Linux Format bounty, but it's far from perfect, and there were a few features I didn't get a chance to implement, so here is a list of things that will be considered at some later stage. Especially if there's interest from the outside world.

• In SUSE 10, colours don't work the way they're supposed to. I suspect this is due to a newer version of PyGTK (2.8) than I tested with (2.6), but not sure yet.
• Undo/redo. Done for 1.1
• Printing.
• Random hints - randomly select a square that can be determined by the numbers on the board. (This is fairly straightforward.)
• Packaged up collections of puzzles.
• The GUI has a few idiosyncrasies that may need to be ironed out. In particular, I'm not sure how well the multiple window structure works. There might be better ways to do it, e.g. put the menus and toolbar in a controller window (à la GIMP) or something similar. The GUI code could generally do with a bit of cleaning up - it kind of evolved as I learned to use PyGTK properly.
• Per-puzzle-size settings, especially font size (the default font is too big to fit 5x5 on the screen).
• Strange (non-rectangular) region and/or puzzle shapes. This will need a change to the save file format.
• There are some more intelligent rules that could speed up the solver. At the moment it's fine for 3x3 puzzles, but non-straightforward 5x5 puzzles take an infeasibly long time. It could even be worth rewriting some parts of it in native code - Python may be dragging its heels in some places.
• The random puzzle generator tends to make puzzles that are classified as at least Challenging, often Tough. I'm not sure whether this is the fault of the generator or the difficulty estimate; possibly a bit of both. Also, I'm not sure how useful the difficulty estimate is for non-3x3 puzzles.
• I could generally use some feedback on which menu options are useful enough to put on the toolbar, whether to add keyboard shortcuts for everything, whether the current behaviour of the arrow keys is intuitive, and so on. Toolbar real estate isn't cheap at the moment, but a different window structure could help that.

An example puzzle (this represents the board shown in the screenshot above):