A friend of mine referred me internally at Google, and I received a call from a recruiter almost immediately (within 2 days).

I was then scheduled for two phone interviews, about a week apart.

Finally, I had an on-site interview that consisted of meeting with five engineers for 45 minutes each, plus a sixth person for lunch. The lunch meeting was not a formal interview, but more of a "get to know Google" session.

You have a genealogy:

1. Describe a data structure to represent it.
2. Given any two people within the genealogy, describe an algorithm to determine if they share a common ancestor. You just need to return true/false, not all ancestors.