NeetCode #139LC-1396MediumArrays & Hashing
← Back to All Problems#139 · #1396 · Design Underground System(设计地铁系统)
📌 Problem Statement & Constraints
Design an underground system supporting
checkIn(id, stationName, t), checkOut(id, stationName, t) and getAverageTime(startStation, endStation). Customers make at most one trip at a time and are guaranteed to have checked in before checking out. Constraints: at most 2 * 10^4 calls.🔒
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