The contest section focuses on various computer competitions at the (advanced) high school level. This will continue to grow for quite some time as I continue to search for other contests on the Net, and convert them to HTML format. Right now, I have mostly questions with a few solutions thrown in where I have not been too lazy to type them up. The sites of most of the competitions provide these with the notable exception of the USACO.
Anyway, look around! The contests are generally listed in decreasing order
of difficulty, but many vary in difficulty from year to year, so look at a
few samples, before writing them off. 
International Olympiad in Informatics
1996: Problems Solutions: 1 2 3 4 5 6
USA Computing Olympiad
Qualifying Round Problems
Competition Round Problems
Qualifying Round Problems
Fall Championship Problems
Winter Championship Problems
National Championship Problems
Fall Championship Problems
Winter Championship Problems
Spring Championship Problems
National Championship Problems
Fall Championship Problems Solutions: 1 2 3 4
Canadian Computing Competition
Round 1 Problems Solutions: 1 2 3 4 5
Round 2 Problems Solutions: 1 2 3 4 5 6
Round 1 Problems
Round 1 Problems
Round 1 Problems Solutions: 1 2 3 4 5
Independent Schools Computer Olympics
