Find longest subsequence in array

Last updated: December 30, 2025

Quick Overview

Given a interval list, find the maximum path efficiently using Sliding Window.

Snapchat
Coding & Algorithms
Software Engineer
Snapchat
December 30, 2025
Software Engineer
Phone Screen
Coding & Algorithms
Easy

131

8

2,167 solved


Given a interval list, find the maximum path efficiently using Sliding Window.

Snapchat uses this problem in the Phone Screen 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
  • Identify the correct data structure and algorithm for the problem
  • Write clean, bug-free code with proper variable naming
  • Analyze time and space complexity correctly
  • Handle basic edge cases (empty input, single element)
  • Communicate your thought process while coding
Key Topics to Cover
Tree structures and recursion
Data structure selection and trade-offs
Hash maps and frequency counting
Common algorithm patterns (sliding window, two pointers, BFS/DFS)
Binary search and divide and conquer
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 your solution change if the input was sorted?
  • How would you modify your solution to handle streaming input?
  • Can you solve this in a single pass?
Sharpen Your Skills on Codemia

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