Amazon Software Developer interview questions

Interview consisted of one phone screen with H/R, two phone interviews with engineers, then followed by a programming assignment. After passing all these hurdles was brought up to the corporate Head quarters for an on site interview. On Site consisted of 4 interviews (three techinical, one soft) which included programing problems and general technical discussions.

I was contacted by amazon recruiter for phone screen. The first phone screen tooks an hour and I was asked question about some C++ question and algorithm. two days later they come back to me and scheduled a second round phonescreen. The process is same as the first one; and guess I screwed up; 2 days (again) later I was informed via email that I failed :(