Amazon Software Development Engineer interview questions

I submitted my resume in a school job fair and got reject. But, HR man emailed me to invite the final on-site interview. In the interview, I met 2 teammates and got one task each. While solving the task, we needed to meet 4 interviews to talk about the task I was doing. To solve my question, I need to use Map. I got rejected from the interview. I think my way to use Map is not good as other members.

The interview itself was 45 minutes long and over the phone with two interviewers. Only one did the talking and was quite nice. They first described what they did at Amazon then asked me about myself. I completed my interview questions in Java using CollabEdit. Overall the experience was a positive one.