QuickBuzz

A few of my friends use FizzBuzz to screen candidates, and that's a good thing because it's really good at weeding out the completely incompetent. The problem comes when you need someone who's more than just competent, you need someone who actually knows something. In those cases, I propose using Quick sort as a 2nd level FizzBuzz problem (or even a replacement for FizzBuzz). Quick sort is simple enough that it can be implemented in almost no time and almost no code by anyone who knows their programming language. It also has the benefit of opening the door for follow-on questions, like how do you avoid the algorithm taking n^2 time if the list is in order or what do you do if the list is too big to fit into main memory.