Amazon | SDE2 ( L5 ) | India | Feb 2024 (Rejected)

Online Assessment

Questions:

1. Simple medium question based on sets.
2. Medium question solvable only using Trie.

Time Taken: Solved both questions in 40 mins.

Sections:

• Section 2 & 3: Behavioral and situation-based questions.

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Round 1: Technical (LLD)

Questions:

1. Two Amazon Leadership Principles (LP) questions.
2. Design Email Domain Server (LLD):
   • Task: Design a system for domain name registration and email creation, including sending emails between users of the same and different domains.

Learnings:

• Don't just watch videos; practice solving problems independently.
• Use tools like draw.io for design practice.
• Discuss your thought process with the interviewer.

Candidate's Approach

• Followed STAR approach for LP questions but struggled to satisfy the interviewer.
• Initially misunderstood the design question; needed clarification.
• Partially solved the design problem with hints from the interviewer.
• Expected to provide a high-level design with database selections and component details.

Interviewer's Feedback

• The interviewer was supportive but emphasized the need for deeper understanding and preparation.
• Suggested that the candidate should practice more independently and discuss choices during the interview.

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Round 2: Technical (DSA)

Questions:

1. Given two nodes of a binary tree, find the distance between them.
   • Tree structure:

   TreeNode{
       int val;
       TreeNode parent;
   }

   • Example:

           1
         /   \
       5       3
      / \       \
     4   8       7

   • Examples:
     • distance(5, 7) output: 3
     • distance(8, 7) output: 4
     • distance(4, 8) output: 2

Time Taken: 35 mins for the tree question, followed by 20 mins for Amazon LP questions.

Candidate's Approach

• First Approach: Used a hashmap to store distances from node1 to root and checked for node2 in the map.
• Second Approach:
  • Added nodes from node1 to root into a set.
  • Iterated from node2 to find the lowest common ancestor (LCA) using the set.
  • Calculated distances from both nodes to the LCA.
• Time & space complexity: O(h), where h is the height of the tree.

Interviewer's Feedback

• The interviewer seemed to have additional questions but time constraints limited the discussion.
• The candidate successfully explained edge cases after the main question.

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