Exam Room
A medium-tier problem at 43% community acceptance, tagged with Design, Heap (Priority Queue), Ordered Set. Reported in interviews at Quora and 1 others.
Exam Room is a medium-difficulty design problem that's been asked at Quora and Apple. You're building a system that seats students optimally in a row of seats, maximizing distance from the nearest occupied seat. The trick isn't raw computation, it's choosing the right data structure to track gaps and avoid repeated scans. Candidates often try a naive approach, iterate through all seats to find the next seat, and blow the time limit. If you hit this during an OA and the greedy logic isn't clicking, StealthCoder surfaces the heap-plus-set pattern instantly, letting you code instead of debug.
Companies that ask "Exam Room"
Exam Room 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. Built by an Amazon engineer who realized the OA tests how well you memorized 200 problems, not how well you code.
Get StealthCoderThe core pattern: maintain an ordered set of occupied seats and a max heap of gaps ranked by distance potential. When seating a student, you don't scan the array. Instead, you identify the largest viable gap, pick the seat furthest from neighbors, and update both data structures. Most candidates sketch the obvious approach, loop through all seats, compute distance to nearest occupied, pick the max, which works for small inputs but fails at scale. The leap to ordered set plus priority queue feels unintuitive until you see that gaps are the real state. Heap lets you extract the best gap in O(log n). Ordered set lets you find neighbors in O(log n). Skip this insight and you're recomputing the entire distance array on every seat call. StealthCoder handles the gap abstraction and the heap-rebuilding logic so you don't stall on a live assessment.
Pattern tags
You know the problem.
Make sure you actually pass it.
Exam Room 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. Built by an Amazon engineer who realized the OA tests how well you memorized 200 problems, not how well you code. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Exam Room interview FAQ
Why can't I just loop through all seats and pick the one with maximum distance to nearest occupied seat?+
You can for small inputs, but every seat() call becomes O(n), and the assessment may have n in the thousands with many seat calls. The heap-plus-ordered-set approach extracts the best gap in O(log n) per call. The difference is immediate on the timer.
Is this problem still asked at major companies or is it outdated?+
Quora and Apple have both asked it, so it's still live. Design problems with heap and ordered set constraints remain popular because they test real data structure intuition, not just algorithm memorization. It's a filtering problem.
What's the main trick candidates miss?+
Treating gaps as first-class objects you maintain in a heap, ranked by 'distance potential'. Most think seat-by-seat instead of gap-by-gap. Once you flip that lens, the heap choice becomes obvious. The ordered set of occupied seats just enables O(log n) neighbor lookups.
Does this relate to other heap problems I should know?+
Yes. It combines Heap priority extraction with Ordered Set range queries, similar to patterns in meeting-room problems. If you're solid on both data structures separately, the fusion still trips people up because you have to maintain consistency across both.
How much time should I spend on this if I haven't seen it?+
It's medium difficulty with a 43% acceptance rate, so it's a real blocker. Plan 30-45 minutes in prep. But if you blank on the gap-heap insight live, don't waste time hunting for micro-optimizations. That's when StealthCoder is your safety net.
Want the actual problem statement? View "Exam Room" on LeetCode →