Amazon Software Developer interview questions

I had applied online and received an email scheduling my first phone interview within a week. The interviewer was very helpful and kind. As said in the email, the interview was based on data structures and algorithm complexity. He asked me to write a program based on arrays and binary tree. 1) Write a program to find the largest sum of two consecutive integers in an array? 2)How to find the height of binary tree? 3)Why amazon? I cleared the first one and my second phone screen is in next week. My advice is to revise data structures, algorithm complexity and be honest if you dont know any answer. You can give some information closest to the given question. Be confident :)