Bucket Sort interview questions
6 bucket sort problems tagged across recent interview reports. Drilled most heavily by netflix, robinhood, and yandex.
Bucket Sort is a non-comparative sorting algorithm that distributes elements into buckets, then sorts each bucket independently. It appears in 6 interview problems and shows up frequently at Netflix, Robinhood, and Yandex. The pattern matters because it's one of the few ways to beat O(n log n) comparison sorts, and interviewers love testing whether you know when to use it. Most candidates default to quicksort or mergesort without considering the constraints. If the input range is known and bounded, Bucket Sort becomes the optimal choice, and the interviewer will expect you to recognize that.
Most-asked bucket sort problems
| # | Problem | Diff | # Companies | Pass % |
|---|---|---|---|---|
| 01 | Top K Frequent Elements | MEDIUM | 43 | 65% |
| 02 | Top K Frequent Words | MEDIUM | 14 | 59% |
| 03 | Contains Duplicate III | HARD | 4 | 24% |
| 04 | Sort an Array | MEDIUM | 3 | 57% |
| 05 | Sort Characters By Frequency | MEDIUM | 3 | 74% |
| 06 | Maximum Gap | MEDIUM | 1 | 49% |
You can't drill every bucket sort variant before the assessment. StealthCoder runs invisibly during screen share and solves whichever variant they throw at you. No browser extension. No detection signature. Built by an Amazon engineer who realized the OA tests how well you memorized 200 problems, not how well you code.
Get StealthCoderBucket Sort shines when you're sorting elements with a known range or distribution. The key insight: instead of comparing elements globally, you partition them into buckets based on their value range, sort within each bucket (often recursively or with a simpler sort), then concatenate. Common variants include counting sort for integers with small range, radix sort for multi-digit numbers, and frequency-based bucketing for top-k problems like Top K Frequent Elements. You'll encounter it most in problems where the constraint hints at a range (e.g., 0 to 1 range, bounded integers) or when frequency matters. Recognition is critical: if you see a constraint like 'numbers in range [0, n)' or 'k distinct values', Bucket Sort is likely faster than comparison sorts. StealthCoder watches for these patterns in live assessments and delivers the bucketing logic in seconds, so you're never caught off-guard by a variant you didn't drill.
Companies that hire most on bucket sort
6 bucket sort problems.
You won't drill them all. Pass anyway.
Bucket Sort is one of the patterns interviews actually filter on. Memorizing every variant in a week is a fantasy. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds, no matter which bucket sort flavor lands in your live OA. 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.
Bucket Sort interview FAQ
When should I use Bucket Sort instead of quicksort?+
Use Bucket Sort when the input range is known and bounded, or when you need linear time. If the constraint specifies a range (e.g., 0 to 1, or 1 to n), or if frequency/distribution is part of the problem, Bucket Sort beats O(n log n). Quicksort is faster for unstructured, large-range data.
How many Bucket Sort problems should I drill before an interview?+
There are 6 core problems tagged with this pattern. Drill at least 3-4 to recognize variants: at least one pure bucketing problem, one counting sort case, and one top-k frequency problem. This covers the range Netflix and Robinhood test.
How do I recognize a Bucket Sort problem in a live interview?+
Look for: explicit range constraints, frequency-based sorting, or a request to beat O(n log n). Problems like Top K Frequent Elements, Sort Characters by Frequency, and Maximum Gap hint at bucketing. If you see 'range [a, b]' or 'k buckets', Bucket Sort is in play.
Which companies test Bucket Sort the hardest?+
Netflix has 7 problems, Robinhood 6, and Yandex 5 that involve this pattern. If you're interviewing there, bucketing variants are non-trivial. Adobe, Atlassian, Box, DoorDash, and others also weight it heavily.
Is Bucket Sort related to counting sort and radix sort?+
Yes. Counting sort is Bucket Sort for small integer ranges. Radix sort is Bucket Sort applied digit-by-digit. All three are non-comparative and linear under the right constraints. Understanding one unlocks the others.