[snikolov]

I doubt it's that bad. It might be that he hadn't done any bit hacking in C in a while. If you haven't coded in matlab for a long time and I asked you (during an interview!) to do random bit hacking, you might feel stumped too. You'd probably want to play around with it for a minute and re-figure it out, but you've got an interview waiting for you to produce an answer right away.