The key click for me was realizing you don't need to simulate every possible path, you just care about what's happening at each location along the route.
Model each trip as two events: a pickup (+passengers) and a dropoff (-passengers) at specific locations. Sort all events by location, and for events at the same location, process dropoffs before pickups to avoid false capacity violations. Then simulate the events while tracking the current passenger count, ensuring it never exceeds the car's capacity.
Pro tip: Clarify edge cases upfront, such as trips with zero passengers or identical pickup/dropoff locations, and explicitly state that dropoffs are processed before pickups at the same location. This shows attention to detail and prevents off-by-one errors.
Confirm the input format, capacity constraints, and whether locations are discrete points. Ask about edge cases like zero-passenger trips or same pickup/dropoff locations.
Convert each trip into two events: a pickup event with +passengers and a dropoff event with -passengers, each associated with its location.
Sort all events by location. For events at the same location, process dropoffs before pickups to correctly reflect that passengers leave before new ones board.
Iterate through sorted events, updating the current passenger count. After each event, check if the count exceeds the car's capacity; if it does, return false.
If all events are processed without exceeding capacity, return true. Optionally, verify that the final passenger count is zero.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.