JAVA SUDOKU SOLVER

Jadoku is a program for solving Sudoku puzzles using Knuth's Dancing Links
algortihm, written in Java and licensed under the 3-clause BSD license. You
can find license details in the LICENSE file, located in the root directory of
the source distribution.

The program solves Sudoku grids by converting them into an instance of the
exact cover problem, solving the exact cover with a Dancing Links
implementation of Knuth's Algorithm X. This is significantly faster than the
previous implementation which used a pencil-and-paper approach.

The program will also detect if a puzzle is unsolvable.

FILE FORMAT

This program can take a list of files as arguments. Each file contains a list
of puzzles, one per line. Each puzzle is a string of 81 digits with no spaces,
representing the cells on a Sudoku grid from top-left to bottom-right. Cells
numbered as 0 represent empty cells.

In the Jadoku GUI, each puzzle will be opened in an individual window.

COMPILATION

Building the sudoku solver is simple. You will need Apache's Ant build system,
and a minimum JDK version of 1.5.

To compile, simply navigate to the root directory of the solver, and enter the
command:

   $ ant

This will produce a jar file, titled "Jadoku.jar", as the output. This jar can
be run by the usual methods; double-clicking the file if you're on Windows or
Mac, or using the command:

   $ java -jar Jadoku.jar [file]...

If you're on UNIX or Linux.

COMMAND LINE TOOL

Jadoku comes with a command line tool as well, which can be invoked with the
command:

   $ java -cp Jadoku.jar Cli [file]...

This tool takes a list of files as arguments. Each file contains a list of
puzzles, one per line. Each puzzle is a string of 81 digits with no spaces,
representing the cells on a Sudoku grid from top-left to bottom-right. Cells
numbered as 0 represent empty cells.

The tool attempts to solve each puzzle, and, if successful, reports the time
it took and the number of guesses (and the number of incorrect guesses). If the
puzzle couldn't be solved, the time is reported as well as the fact that the
puzzle wasn't solved.

Once the program finishes execution, the total amount of time spent solving
puzzles is displayed.

INSTALLATION

The jar file generated by Ant is entirely self-contained, so you can feel free
to copy it anywhere you'd like.