README

What is Sudoku?

Sudoku, also known as Number Place, is a logic-based placement puzzle. The aim of the puzzle is to enter a numerical digit from 1 through 9 in each cell of a 9x9 grid made up of 3x3 subgrids (called "blocks"), starting with various digits given in some cells (called "givens"); each row, column, and block must contain exactly one instance of each digit. For more information you can visit "http://en.wikipedia.org/wiki/Sudoku".

What is CSudoku?

CSudoku is a command line Sudoku solving program written in the C programming language. It solves the popular 9x9 versions of Sudoku using Donald Knuth's Dancing Links algorithm. It was created as a fun exercise in computer programming and not necessarily to be a program useful to anyone in particular since there are many other Sudoku solving programs that are more refined and have many more features than this program would ever dream of having. CSudoku is distributed under the terms of the GNU GPL (see COPYING for details).

Installation

unpack csudoku-1.0.tar.gz
cd csudoku-1.0/src
run make

Windows users who don't wish to build the program from the sources can simply copy the program sudoku.exe to whatever directory they wish and run the program there.

Usage

To run the sudoku program you will first need to install it using the steps as outlined above. Now, assuming you are in the directory csduoku-1.0/src, invoke the command:

./sudoku < infile

where infile is an input file containing 1 or more 9x9 Sudokus. For the format of the infile you can check out the file top95. In fact you can use the top95 file to test the program. By invoking the command:

./sudoku < ../top95

you should see some input and output details and at the end under "Overall Statistics" it should read

...
95 out of 95 were valid
0 has no solution(s)
95 had unique solution(s)
0 had multiple solution(s)
...

If this was done successfully you can now use the program to solve whatever Sudoku puzzle is giving you trouble. Enjoy!

Contact

Have questions or suggestions, please contact me at: crooks_dwayne at yahoo dot com