Su14oku

This is an SDL - implementation of the famous Sudoku puzzle. The motivation behind programming this game was the challenge to come up with an efficient way of generating Sudokus that are clearly solvable. This means, that no guessing has to take place in order to solve the generated Sudoku.
Thanks to a whole lot of tuning and experimenting with a big amount of different algorithms Su14oku now manages to generate 9x9 sudokus on the hardest level in less than 2 secs on a Celeron 2.5 Ghz.
In order to test the results of my coding I included a bigger puzzle size ( 16x16 instead of the common 9x9 ) as well - I don't expect anyone to solve one of these though...;-)
As always, I used SDL (1.2.9 this time) to produce OS-independent graphics - code, which allows me to present you binaries for Linux and Windows.

Here's how this kind of puzzle works:

The layout of the game consists of 3 rows and 3 columns holding 9 cells each (which leaves us with a 9x9 matrix).
Goal of the game is to fill all cells without violating the condition that each row/column and 3x3 subsection has to hold exactly one copy of each number.

WARNING: Game is highly addictive ;-)