Microsoft Software Development Engineer interview questions

Applied online. Got an email saying they want to do the phone interview. The phone interview was easy, general questions. Microsoft flew me out to Redmond. Gave me hotel room, car rental. Then did the one day revolving interviews, many managers. Mostly programming and skills question. Lunch was provided. Got an offer a couple of weeks later. However they still had to find a group that needed me. Got another phone interview from the manager (about 1 hour).

The interviewer first asked me some questions about what class I've taken and since he was an alumni we exchanged some fun things about some courses we've both taken. Then he gave me a question on tree traversal . The tree was weird, each node points to a parent, two children, and siblings.