We used this lego sumo this program to participate in the gisutech competition (www.gisutech.com) and we won a gold medal.
You can download our program on the https://github.com/mikailalici/nxtsumo
What is lego sumo : Two self-controlled robots compete and try to push their competitor off the field. The field is round and the interior surface is painted black and is bordered with a white margin. In each competition, two robots compete. One competition consists of three rounds. If there is a lack of time the matches can be shortened to one round instead of three.
Lego Sumo Video: