Circular Buffer
Domain: Data Structures
🎯 Motivation
When you need a fixed-size buffer that overwrites old data when full — audio streams, log rotation, sensor data — a circular buffer cycles back to the start.
📋 Concrete Example
Buffer of size 4: positions [0,1,2,3]. After filling all 4, the next write goes back to position 0, overwriting the oldest data. A write pointer cycles around.
🔗 Analogy
A circular running track with 4 lanes. When the runner in lane 4 finishes, the next runner starts again in lane 1, replacing the oldest runner. The track never grows.