Minimum Number of Arrows to Burst Balloons
A medium-tier problem at 60% community acceptance, tagged with Array, Greedy, Sorting. Reported in interviews at Instacart and 3 others.
You've got an array of balloons, each with a start and end coordinate on a number line. You need to fire the minimum number of arrows to burst them all, and each arrow bursts every balloon it passes through. It sounds simple until you realize the greedy choice isn't obvious. Instacart, Flipkart, Goldman Sachs, and TikTok all ask this one. The acceptance rate sits at 60%, which means a lot of candidates overthink it or miss the sorting trick that makes it trivial. If this problem hits your live assessment and you blank on the pattern, StealthCoder surfaces a working solution in seconds, invisible to the proctor.
Companies that ask "Minimum Number of Arrows to Burst Balloons"
Minimum Number of Arrows to Burst Balloons 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 trap is trying to maximize coverage with each arrow. The actual move is greedy on the end coordinate. Sort balloons by their end point, fire an arrow at the first balloon's end, then skip all balloons that overlap with it. Fire again at the next non-overlapping balloon's end. The algorithm is Sorting and Greedy applied in sequence. Most candidates either sort by start (wrong), try dynamic programming (overkill), or implement the greedy logic but fumble the overlap check and integer overflow on coordinates. The pattern is pure sorting plus a single pass. StealthCoder covers the version where you have to handle edge cases around overlapping intervals and coordinate precision, so you don't stall mid-interview.
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Minimum Number of Arrows to Burst Balloons 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.
Minimum Number of Arrows to Burst Balloons interview FAQ
Why does sorting by end coordinate work instead of start?+
Sorting by end is greedy because it minimizes the space taken by each balloon. Once you place an arrow at a balloon's end, you've covered the maximum possible range for that balloon. Any balloon that doesn't overlap with that arrow will require a new one. Start coordinate doesn't give you this property.
Is this problem still asked by FAANG and tier-1 companies?+
Yes. Instacart, TikTok, and Goldman Sachs have all asked it. The 60% acceptance rate suggests it's a solid medium-difficulty screening question. It tests both sorting and greedy reasoning, so it remains in active rotation.
What's the common mistake candidates make?+
Overthinking the overlap check. Candidates often try to track all balloons bursted so far or use interval merging logic. The correct approach is simpler: if a balloon's start is beyond the last arrow position, fire a new arrow at that balloon's end. One pass, no extra data structures needed.
How does this relate to other greedy interval problems?+
It's similar to meeting rooms and interval scheduling, but the twist is that arrows burst everything they touch. That symmetry means greedy-by-end is optimal here. Other interval problems sometimes require different strategies, so understanding why end-sorting works here matters.
What edge cases trip up implementations?+
Integer overflow on coordinates (balloons can have massive ranges), empty arrays, and single-balloon inputs. The overlap condition itself is also a trap: you must check if the next balloon's start is strictly greater than the arrow position, not equal. Off-by-one errors are common.
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