Find top-K frequent elements in a stream
Quick Overview
This question evaluates understanding of streaming algorithms, frequency estimation, and data-structure-based top-K selection, emphasizing space/time and accuracy trade-offs when processing large or unbounded data.
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Feb 25, 2026, 12:00 AM
Software Engineer
Onsite
Coding & Algorithms
3
0
You receive a large stream of items (e.g., integers or strings) that may not fit in memory. Design an algorithm that can return the top K most frequent items.
Requirements:
- Provide an exact solution when the number of distinct items fits in memory.
- Provide an approximate solution when distinct items are too many (state the error/accuracy tradeoff).
Explain time and space complexity for both approaches.