No very difficult questions. Just take it easy and enjoy the process. Almost all of the question are from the <Cracking the Coding Interview>. A quick response and emphasize on the issue of efficiency are important. I think Facebook love to ask questions about the tree structure and some practical questions because they are realistic problems. When you prepare and practice, do remember that efficiency is a really significant issue, much more important than simply giving an answer. And I would like recommend another book <Programming pearls>. Maybe the book is not a hard one to read, but the thought of the author, why the author wants to improve some algorithm and how he solves problems are really fantastic. The questions are from realistic problems and the book is really worth reading several times. It benefits me a lot.
