So there we were, building a tree out of a forest of existing smaller trees or such. That was after they couldn't find my resume, and used a 5 year old one they found some place. They seemed annoyed and tired. By that time I felt nothing short of me proving P!=NP would have help changed their mood. I mean, they didn't even ask me what I knew, what I worked on lately. Heck, I could have been herding goats for the previous 5 years, but if I could have solved that tree problem, well, Googleplex here I come, I could have been herding goats there, maybe as part of some a green eco-initiative project...
I guess half way through I just kind of decided that Google must be a pretty bad place to work at and kind of gave up. I was tempted to ask them how often they had to build the tree out of subtrees at Google. Or in this case how many times did they really have to invert the binary tree, but I am nicer that than, maybe they really did have a pretty shitty day.
Ever since then I've declined to interview at Google. I get contacted every year like clockwork "Wanna try again?", "No thanks, good luck inverting binary trees though..."