Validate interval list sorted
Last updated: April 23, 2026
Quick Overview
Given a list of intervals, write a function to determine if the list is sorted in non-overlapping order. The input will be a list of intervals represented as pairs of integers, where each pair [start, end] indicates the start and end of an interval. The output should be a boolean value indicating whether the intervals are sorted and do not overlap.
Lyft
April 23, 202632
4
4,814 solved
Given a list of intervals, write a function to determine if the list is sorted in non-overlapping order. The input will be a list of intervals represented as pairs of integers, where each pair [start, end] indicates the start and end of an interval. The output should be a boolean value indicating whether the intervals are sorted and do not overlap.
Lyft 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
How to Approach This
- Clarify input constraints and edge cases before writing code.
- Walk through your approach verbally and confirm with the interviewer before coding.
- Start with a brute force solution, then optimize. Mention time and space complexity.
- Test your solution with examples, including edge cases like empty input or duplicates.
- Consider common patterns: sliding window, two pointers, hash map, BFS/DFS, dynamic programming.
Possible Follow-up Questions
- 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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Practice DSA ProblemsSample Answer
Problem Analysis
To solve the problem of validating if a list of intervals is sorted in non-overlapping order, we can identify that this problem exhibits a pattern similar to the 'two pointers' technique. This is beca...
Approach
- Iterate through the list of intervals starting from the first interval.
- For each interval, compare its start with the end of the previous interval.
- If the start of the current interval is les...
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