I've always said that if someone asked me to code up the binary search algorithm as part of an interview, I'd bonk them on the nose. Why? Why get so upset over an obvious algorithm that anyone can explain? Because there are always bugs: Official Google Research Blog: Extra, Extra - Read All About It: Nearly All Binary Searches and Mergesorts are Broken

Now a whole new class of bugs: integer overflow.

Hmm. Now I'm almost hoping someone does ask me to code up a binary search at my next interview, just so that I can do a safe mid-point calculation and see them contemplate whether or not to ask me why in the world the line is coded that way.