A Sudoku Solver
How does a computer scientist play sudoku? Right: he does a couple by hand, and then he writes a program that solves them for him. Here you are. :-)
This is a Java applet, so you need to have Java installed.
If you care: the source is contained in the jar-file, which
is also executable with java -jar sudoku.jar
as a Swing application.
Since I like javadoc I documented it very well for a quick sparetime project.
The basic idea is rather easy - the computer keeps track which digits are still
possible for each field if you exclude the digits that are known for the 3x3 square,
the line and the column. If only one digit is possible it is marked as known and
the other fields are updated accordingly.