UVa Online Judge is a problem archive with over 3500 problems.
Start off by reading the the introduction.
Are there any problems that you would like us to do? You can request problems through the contact form.
A list of the solutions available on this site:
Problem Set Volumes
Volume I
100 – The 3n + 1 problem
102 – Ecological bin packing
Volume II
Volume IV
Volume V
Contest Volumes
Volume C
10055 – Hashmat the brave warrior
Volume CI
Volume CII
10229 – Modular fibonacci
10268 – 498-bis
