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Last updated: January 15, 2026

Quick Overview

Determine if a given binary tree satisfies the symmetric property.

MongoDB
Coding & Algorithms
Software Engineer
MongoDB
January 15, 2026
Software Engineer
Onsite
Coding & Algorithms
Medium

23

11

4,921 solved


Determine if a given binary tree satisfies the symmetric property.

MongoDB uses this problem in the Onsite to evaluate your algorithmic thinking. They expect you to discuss multiple approaches, analyze trade-offs between them, and implement the optimal solution with clean, readable code.

What the Interviewer Expects
  • Recognize the underlying problem pattern (sliding window, two pointers, BFS/DFS, etc.)
  • Discuss multiple approaches and trade-offs before coding
  • Implement an optimal solution with clean, production-quality code
  • Handle all edge cases including boundary conditions and invalid input
  • Optimize both time and space complexity with clear justification
  • Test your solution systematically with well-chosen examples
Key Topics to Cover
Graph algorithms and traversal
Binary search and divide and conquer
Sorting and searching
Dynamic programming and memoization
Time and space complexity analysis
How to Approach This
  1. Clarify input constraints and edge cases before writing code.
  2. Walk through your approach verbally and confirm with the interviewer before coding.
  3. Start with a brute force solution, then optimize. Mention time and space complexity.
  4. Test your solution with examples, including edge cases like empty input or duplicates.
  5. Consider common patterns: sliding window, two pointers, hash map, BFS/DFS, dynamic programming.
Possible Follow-up Questions
  • How would you test this solution thoroughly?
  • Can you solve this in a single pass?
  • How would your solution change if the input was sorted?
  • How would you modify your solution to handle streaming input?
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