Amazon Software Development Engineer interview questions

Applied for the Silk team via their website. Got a call within 2 weeks. There were a few clashes in the dates as my wife was going to deliver during that period, but they very kindly rescheduled. I had 2 phone screens and was then called to Seattle for full-day interviews. Phone screen was done using collabedit tool, and on-site interview required writing code on white-board. 1st Phone screen: Write a power function. All edge cases like overflow, different values of powers (+ve, -ve, zero) need to be handled. Have to give most efficient solutions. 2nd Phone screen: Write a function that, given an array and a number as input, finds all pairs in the array that add up to that number. Number can be +ve/-ve. Write most space (or) time efficient algorithm. How will it handle duplicate pairs. On-site interviews: 1. Given a 2D array (which has initially all false values), fill it up with 'X' true values placed randomly in it (like minesweeper game). Most efficient alog expected with handling of ALL edge cases. 2. Implement a simple contacts application in which one can search via First name. Most efficient alog expected with handling of ALL edge cases. 3. Bar-raiser: Given a log file from a website which contains the user ID and the accessed URL, find the TOP "sequence" of 3 urls amongst ALL visitors of the website. The sequence of urls have to be in sequence as they are accessed. 4. Experience related questions by Team manager over lunch. 5. Implement classes for a website that can be used for building your own computer. Eg: If a user selects a motherboard, it should filter out all the incompatible CPUs etc. You have to implement various classes that can be used for implementing this functionality.

Talked to representative on career fair on campus, then took an online assessment (which contains 3 problems, 30 mins for each, mostly algorithm problems). About two weeks later got onsite interview opportunity in Seattle. Onsite interview has 4 rounds, 45 mins each, including algorithm, data structure and design problems.