FA-67508 / Elevator dispatch scheduling / Member archive

Car call registration and cancellation: double press cancel · case 03

The last remaining call is cancelled by a double press, or earlier calls cannot be cancelled.

Member previewVariant 3 · 3 implementations · 8 checks per implementation

Case contract

Car buttons are processed in order. Pressing the current floor with doors open reopens the doors. Floors outside 0..floors-1 are invalid. Pressing an already registered floor cancels it, unless it is the only call (kept). With load under 20 kg, a new call is refused as nuisance once five calls are registered. Otherwise the call is registered. Return the sorted calls and the per-press log.

Why this case matters

Lift group controllers make these decisions many times per minute; a wrong answer strands passengers, wastes trips or overrides a safety rule.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: double press of the only call	`{"calls": [], "log": ["registered", "cancelled"]}`	`{"calls": [3], "log": ["registered", "kept"]}`	Failed

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