Like jsnell, I spent weeks’ worth of nights beating my head against the problem I selected, and the solution I eventually came up with was not good enough to earn me an interview.
I gather that someone with a stronger theoretical CS background than myself would have spent an hour looking at the puzzle, said “Ah, this can be modelled as a graph and solved by applying the Flibblewhiz Heuristic!”, spent another hour coding up a first draft of the solution, and a third hour optimizing and cleaning up the code.
My ego has survived the blow of learning that I am not awesome enough to work for ITA, but I wish I had figured that out sooner.
