Find kth largest element in matrix

Last updated: June 9, 2026

Quick Overview

Given a binary tree, find the cycle efficiently using DFS.

Airbnb
Coding & Algorithms
Machine Learning Engineer
Airbnb
June 9, 2026
Machine Learning Engineer
Onsite
Coding & Algorithms
Hard

46

11

2,649 solved


Given a binary tree, find the cycle efficiently using DFS.

Coding interviews at Airbnb focus on problem-solving approach as much as the final solution. The interviewer wants to see you break down the problem, consider edge cases, and optimize iteratively. Communication throughout the process is key.

What the Interviewer Expects
  • Quickly identify the optimal approach and its theoretical basis
  • Handle complex algorithm design with multiple interacting components
  • Write concise, elegant code under time pressure
  • Prove correctness of your approach and discuss alternative solutions
  • Optimize beyond the obvious: discuss constant factor improvements
  • Address follow-up variations and explain how the solution generalizes
Key Topics to Cover
Dynamic programming and memoization
Sorting and searching
Edge cases and input validation
Graph algorithms and traversal
Binary search and divide and conquer
Common algorithm patterns (sliding window, two pointers, BFS/DFS)
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 parallelize this solution?
  • Can you solve this in a single pass?
  • What if the input doesn't fit in memory?
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