Holding the Center

A hard Python interview practice problem on DataDriven. Write and execute real python code with instant grading.

Domain

Python

Difficulty

hard

Seniority

L5

Problem

A latency monitor emits a reading after every request, and a live dashboard refreshes the median of all readings seen so far each time one arrives. Given `stream`, the readings in arrival order, return the running median after each reading, taking the average of the two middle values whenever an even number of readings has arrived. Each median comes back as a float, and a stream of a single reading reports that reading itself.

Summary

The middle value keeps moving as new data arrives.

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