Non-overlapping Intervals
A medium-tier problem at 56% community acceptance, tagged with Array, Dynamic Programming, Greedy. Reported in interviews at Verkada and 7 others.
Non-overlapping Intervals shows up in live assessments at Verkada, Instacart, Capital One, J.P. Morgan, and Goldman Sachs. You're given a list of intervals and need to remove the minimum number to make them non-overlapping. The acceptance rate sits at 55%, which means almost half the candidates who see this problem in the wild either time out or submit a wrong greedy choice. The trick isn't dynamic programming, even though it's listed as a topic. Most candidates get trapped there and run out of time.
Companies that ask "Non-overlapping Intervals"
Non-overlapping Intervals is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Made by an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too.
Get StealthCoderThe correct move is greedy, not DP. Sort intervals by end time, then iterate left to right, keeping an interval only if its start doesn't overlap with the last kept interval's end. The pattern: when you have a choice between multiple valid intervals, always pick the one that leaves the most room for future intervals. That's what 'end time first' buys you. The pitfall is overthinking it as an optimization problem or trying to brute-force subset combinations. If you hit this problem live and the greedy approach doesn't click immediately, StealthCoder runs invisibly during your assessment and surfaces the sorted-by-end-time solution in seconds, letting you move to the next problem instead of burning 20 minutes on wrong recursion.
Pattern tags
You know the problem.
Make sure you actually pass it.
Non-overlapping Intervals recycles across companies for a reason. It's medium-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Made by an Amazon engineer who watched the leaked-problem repo become an industry secret. He decided you should have it too. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Non-overlapping Intervals interview FAQ
Is this really just a greedy problem or do I need DP?+
It's greedy. Dynamic programming will time out on large inputs. Sort by end time, iterate once, keep non-overlapping intervals. The DP framing is a distraction. Greedy works because choosing the interval that ends earliest always leaves the most room for future selections.
Why does sorting by end time matter more than start time?+
Start time doesn't tell you when the interval frees up a slot. End time does. By prioritizing intervals that finish earliest, you maximize remaining space for future intervals. Start time sorting will fail test cases where earlier-starting intervals block later compatible ones.
How often do top companies actually ask this?+
Eight major firms have reported asking it: Verkada, Instacart, Capital One, J.P. Morgan, Snowflake, Goldman Sachs, Zoho, and Yandex. It's not rare. It's the kind of medium-difficulty greedy problem that slots into phone screens and OAs.
What's the most common wrong answer?+
Sorting by start time, then greedily picking intervals. Looks logical, fails edge cases. Another common mistake is attempting interval DP (counting overlaps recursively), which works for small inputs but times out. The 55% acceptance rate reflects both traps.
How does this relate to the other topics listed?+
Array and Sorting are the tools. Greedy is the strategy. Dynamic Programming is listed because some candidates try DP and pass small test cases, making it a seductive wrong approach. Master the greedy insight and you'll skip the DP dead-end entirely.
Want the actual problem statement? View "Non-overlapping Intervals" on LeetCode →