The biggest issue with these puzzle questions is they are easy to memorize and encourage solving in the shortest amount of lines of code.

I don't know why people rely on them at all because most candidates they hire probably have just went on pythonchallenge or interviewstreet and learned all the solutions to popular problems and then went to the interview or even learned the solutions by going to enough interviews.

I want someone who can think on their own (not memorization) and can write good code (read: not shortest lines possible).