## Interactive Sudoku Solver

This Java applet illustrates the process of solving a Sudoku riddle.
The applet **requires Java 5.0 or higher**.
Click on the applet and enter the the numbers by moving the mouse over a field and
pressing a key. Clear a number with space.

The program will display entries that are without alternative because
of Sudoku's constraints in green. Click on these entries to commit them.
Often, commiting an entry will allow new non-ambiguous entries to be found.
If Sudoku's rules are violated, e.g. because two '1's are in the same row,
the violations will be marked in red. A field that is still not commited, but
for which no number at all is possible, is marked by a red star.

You can save up to five Soduko states, and restore them with the respective
button. If you enable "Advanced strategy" a second strategy is used on top of the standard
one. It is based on groups of fields instead of single fields. Only in rare
cases however does this strategy actually supply additional useful constraints.
If you enable the check box "Show possibilities", the numbers that are
determined as being possible for a field by the solver are shown in blue.
Only up to 3 possibilites are shown. Fields where still more possibilities are
remain blank for reasons of space and conciseness.

Have fun!

### Info

Author: Torsten Nahm

The applet jar also contains the source. The class Sudoku is
a well structured solver, which uses general principles and abstracts
from the geometry of the grid. The GUI however is basically a quick hack.
The documentation in the code is extremely terse, but it should still
possible to understand it. The jar also runs directly as application.

I place the applet into the public domain.