Improving on saddleback search
This is a very interesting topic, and worth some implementation efforts. A LOT OF algorithmic thoughts are introduced in this essay and I can barely keep up with them.
Interestingly, the author said he asked about saddleback search in the entry test for Oxford University. I have to say if it was me I must do it badly.
So what is important is the idea -- the ability to come up with a solution and develop it. Esp. for Haskell, the algorithm itself can be surprisingly short, so implementation shouldn't be a problem even during the process of interview.