Amazon Non Software Development Engineer interview questions

After an online application, I was contacted by a technical recruiter who set up an appointment with a team member for a phone technical interview. The interviewer asked brief questions about my background and then proceeded with the tecnical questions. The technical question was regarding binary search trees. The binary search tree duplicate keys identification and management were the main topics of the interview. The other question was about how to find and validate a tree as a BST given a range of input parameters.