Amazon Software Development Engineer, interview questions

After 3 phone fairly technical interviews about OOP and string related questions, I was invited to Seattle to answer a few more string and array related questions. After 1:1 interviews and was told later that I was not a fit for the team within 12 hours of returning back home.

I didn't do well in the 1st phone interview. But it was fairly easy. Only thing required is good preparation on Data Structures and Algorithms. The interviewer was very professional and nice person. He called me on time, made me confortable in all his questions. I didn't prepare anything before interview but I strongly recommend others to prepare well atleast for 1 month to crack your dream job. 1. What is stack? How do you implement stack using linkedlist? Analyze ur algortirhm for space and time complexity. How do u make it run in O(1)? 2. Some question on Binary tree traversing. I didn't even understand the question properly. But the interviewer tried his best to make me understand the question 2. Design Book shelf.