Overlapping subscription or session windows need collapsing into clean periods, and a naive self-join is quadratic. The signal is the gaps-and-islands trick: a running max end-time to mark where each new island begins.
Updated Aug 2026 · Grounded in real Applied AI Engineer interview loops and written to a senior-engineer editorial bar.
Overlapping subscription or session windows need collapsing into clean periods, and a naive self-join is quadratic. The signal is the gaps-and-islands trick: a running max end-time to mark where each new island begins.
No lesson covers this question directly yet. These teach the surrounding topic from the beginning.
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