Google Software Engineer, Ph D interview questions

I had a hour long phone interview where the reviewer asked a general algorithm question and analysis about the question. I then had an onsite interview with 5 hour-long interviews that were of the same format.

The first stage was the phone screen. The question was fairly simple, related to addition with linked lists Couple of weeks later, I traveled for the on-site. The on-site questions were quite tough. Array rotation, trie datastructure, questions related to design, calculating the area of rectangle etc etc