Sign up at topcoder.com (https://www.topcoder.com/reg/) and do a BFS (Breadth First Search) of their Algorithm (Single Round Matches) SRMs (http://apps.topcoder.com/wiki/display/tc/Algorithm+Overview).

Oh and if you want to brush up on your Algorithm Basics (http://community.topcoder.com/tc?module=Static&d1=tutori...).