Facebook Hacker Cup is open for registration now. Frankly speaking, if you love programming, you should try it. I have joined this contest last year. You may mislead by the contest name. Actually it is not related to "hack" anymore. It is just a purely programming competition. Understanding the question, solve the problem with your prefer programming language, download the data set from facebook and submit your result, that is.
Comparing with Google Codejam, I feel the question from facebook is much more easy to understand. But since you have to submit your answer within certain time, you have to optimize the running process of your code. Most likely there is a math formula or philosophy behind. If you didn't notice it, I bet your code cannot return the result in time.
Anyway, get it a try if you love programming.
Registration: https://www.facebook.com/notes/facebook-engineering/announcing-facebooks-2012-hacker-cup/10150468260528920
