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Leetcode 1396. Design Underground System

Design a system that records passenger check-ins and check-outs and returns the average direct travel time between two stations. The core challenge is maintaining active check-ins per passenger id and aggregated travel-time statistics (sum and count) per station-pair to answer getAverageTime queries efficiently.

Asked at:

Axon

Bloomberg

Bloomberg

Ramp


Question Timeline

See when this question was last asked and where, including any notes left by other candidates.

Mid April, 2026

Bloomberg

Bloomberg

Senior

Mid March, 2026

Axon

Senior

Early March, 2026

Axon

Mid-level

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