Amazon Intern Software Engineer interview questions

I had a friend hook me up with an interview from my university. I am a junior this year, and I don't believe that my resume would have gotten noticed otherwise. They came to my campus and conducted a 90 minute interview where two interviewers had me do 2 fairly difficult coding problems each (full out in my language of preference). I thought they weren't interested in me but heard back after one night that my interviewers were very impressed with me.

Submitting application online and about a week later was asked to schedule a phone interview. The interview consisted of two different calls each about 45 minutes long with a 15 minute break between them. The two callers were both very friendly and easy to understand. They were almost entirely technical in nature. Some questions were just explaining how you would solve a problem and some were writing code. Questions included how to implement C++ set insert and access functions, how to find if two numbers in an array sum to the same number and some object oriented design questions.