Amazon Interview Experience for SDE-1

Hi Guys, sharing my Amazon drive experience for SDE 1 role 2021.

Round 1(Online Test): Online test containing 4 parts:

• A. Error correction: A code will be given, and you need to correct the errors so that it gives the desired output.
• B. Coding: 2-3 codes from medium to hard level.
• C. Workstyle assessment: This will contain situational questions.
• D. Reasoning.

Round 2(Interview 1): 2 questions, 1 hour. The interviewer was very cool and comfortable, was SDE1.

Questions asked were:

1. There are cars on the x-axis of different sizes. Cars are represented by an array of integers where the direction is represented by the sign of the integer and the size is represented by the absolute value. If the cars collide, the smaller car gets destroyed. All the cars move with equal velocity. Find the final set of cars that will remain. (Soln: Use stack)
2. Given a binary tree, find the maximum sum of the elements such that no two node elements are taken from consecutive adjacent layers. After I solved this, the question was modified to find the maximum sum such that no two adjacent node elements are taken in the sum. 

Round 3(Interview 2): 2 questions, 1 hour. Interviewer was not a very good one, probably SDE2.

Questions asked were:

1. Given a binary search tree, replace all the node elements with the sum of the elements greater than it.
2. Given a linked list, sorted according to the absolute value of the nodes, sort it by actual values.

Round 3(Interview 3): 1 hours. Interviewer was 6 years of experience in Amazon and SDE 3. He was very friendly.

1. Started with a light discussion about the interviewer, and then about me. 
2. Discussed the projects. 
3. Asked me a situation where I faced technical problems and how I managed them. 
4. Asked me a technical question for implementing a database with key value pairs that can be stored efficiently where the key and value pairs are only valid for a specific time. Modified the version of the question every time to make it more efficient. It includes implementation of hashing, dictionary, garbage collection, and heap.
5. N. B. In all the interviews, you are required to tell the approach first and if the interviewer is satisfied, then only you will be able to write code. All the interviews were on the amazon chime platform for audio-video and shared whitespace for writing code. No language bar.

Tips: All the interviews were based on data structures. You can always ask the interviewer for clarification.