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Median in Data Stream is a hard coding interview question covering heap, design — the kind asked at FAANG (Facebook/Meta, Apple, Amazon, Netflix, Google) and AI-first companies like Anthropic, OpenAI, and Nvidia.
Design a data structure that supports adding integers one at a time and finding the median in O(log n) per add and O(1) per median query.
Example: addNum(1), addNum(2), findMedian() = 1.5 addNum(3), findMedian() = 2.0
Used in streaming analytics, real-time monitoring systems, and online algorithms.
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