In 2007, I participated in the Informaticup 2007 programming challenge. Our team consisted of Joachim Breitner, Lucas Lürich, Mathias Zwingmann and myself. We solved the ``Cross Number Puzzle'' problem. We entered the final round and won the second place.
You can find the Python source code of our solution. It is licensed under the GPL. The code and comments therein is written in English. Additionally, you can download our documentation and the slides of the talk. These, however, are in German.