Amazon Software Development Engineer interview questions

It was on-campus interview. I applied before the school career fair and got scheduled the interview during it. There were two questions asked by two different interviews. The first question was: given the inorder traversal of a n-ary tree where every node can have either n or 0 children, and is marked "p" if that node has n children, or marked "q" if that node has 0 children, try reconstruct that tree. The second is a design question: given two huge user action logs where each log item has a user id, a document id and access time, try find out the documents that are accessed by two or more users and on two or more different days.

Referred by a friend of mine who is an employee. A few days following the referral I was contacted by a recruiter who asked for a current version of my resume and gave me an overview of what the team I was interviewing for did. A few days later I had a phone interview in which we discussed my background as well as solving a coding problem live on colabedit.com. About half a week after the phone I was asked to fly up to Seattle for an on-site interview. This consisted of 4 back to back interviews (including one lunch interview). The lunch interview is all behavioral. Of the other three, 2 were about 33% behavorial, 66% whiteboard coding. The last interview felt more like a knowledge test, being asked a series of basic algorithm and data structure questions pretty rapid fire. Having told them I had other offers outstanding, the recruited informed me that they would have a decision within the next two days. Received their decision by call the day following the interview