Company: Amazon Development Centre India

Amazon Interview & Written Test Questions Paper 2012

Aptitude test: 45 minutes
Technical test: 45 minutes

Details of types of questions asked in each of the sections:
The aptitude test had questions that concerned the subject and ample time was available to attempt all of them.
The technical written test comprised of two coding problems. The problems were really simple but the actual emphasis was upon handling of all cases, especially edge cases. It was expected that the code should be flawless and handle all NULL pointers without ending up throwing a segmentation fault.


There were a total of 4 rounds of interviews held each lasting anywhere from 30 min to an hour. Following were the questions asked.

Round 1
1. Reverse a linked list using no extra memory or recursion (a very easy one to begin with)
2. Given a linked list, construct a tree whose inorder traversal would be the contents of the linked list.

Round 2
With three files, each containing a day’s data on the customers’ page visiting pattern on a site, determine all customers that visited the site on exactly 2 days and viewed more that 3 distinct pages. The data was available as key-value pairs of customer IDs and page numbers.

Round 3
1. Given a string of the form “aaabcc”, convert it to the form “a3b1c2″ without using any extra memory.
2. Given inorder and postorder traversal of a binary tree, trace the construction of the tree. Comment on the complexity if this construction is performed non-recursively.

Round 4
1. Given a binary tree, pre-process it to be able to determine any node’s inorder successor in constant time.

At all times, the interviewer stressed on writing the code that not only handles the general cases but any of the special or edge cases. Lastly and most important of all, the biggest criterion for evaluation was the complexity of the algorithm proposed.


There was not an explicit HR interview round and one of the interviews comprised of a few questions that can broadly be categorized under HR. These were the ones that are most commonly asked.