Amazon Software Development Engineer, interview questions

Was scheduled for a phone interview round last week , a week after I applied. The interview started with resume scanning and the interviewer asked questions on my projects, which I answered confidently. Later, I was asked about Linked List, Binary trees. He asked me what big oh notation meant, and the time complexities of linked list and binary trees. I was asked what was the worst case scenario of a Binary Search tree. He then asked me what balanced and unbalanced binary trees were, and asked me to write a code on self balancing binary trees. I have not received a reply about the outcome for the phone interview since last week My perception is that the company looks for applicants who demonstrate a 'can do it attitude' when given a tough problem.

Questions they asked were very simple. Their interviews are VERY technical. They grill you even on phone. I was asked all the basic concepts of Java and 2 programs 1. What kind of classes will a Library program consists of. 2. Write a program to reverse an array. Also some other questions were Explain some issues / bugs you resolved in your current project.