At a hill station, the parking lot is one long driveway snaking up a hillside.…
2009
At a hill station, the parking lot is one long driveway snaking up a hillside. Cars drive in and park right behind the car in front of them, one behind another. A car cannot leave until all the cars in front of it have left. The parking lot is more like:
- A.
An array
- B.
A stack
- C.
A queue
- D.
A linked list
Show answer & explanation
Correct answer: C
Concept
A queue is First-In-First-Out (FIFO): the item that entered earliest is always the first one that becomes free to leave.
A stack is Last-In-First-Out (LIFO): the item that entered most recently is always the first one that becomes free to leave.
An array is direct, index-addressed storage, and a linked list is a pointer-chained sequence of nodes — neither imposes any arrival-order rule on removal by itself.
Application
Each car parks immediately behind the car that parked just before it, so the parking order fixes one strict single-file line — the setup itself calls the earlier-parked car "the car in front" of the one that follows it.
The departure rule says a car cannot leave until every car "in front of it" has left — that is, until every car that parked earlier than it has already left.
So the earliest-parked car is free to leave first (no earlier car to wait on), the next-earliest can leave only once the first one has gone, and so on: cars leave in exactly the order they arrived.
Cross-check
This is the opposite of stack (LIFO) behaviour, which would require the most recently parked car to leave first; here the departure rule ties directly to arrival order, not its reverse.
Array and linked list describe storage/traversal mechanics, not an enforced entry-order-equals-exit-order rule, so neither models the constraint in the stem.
Enter-order-equals-exit-order is exactly First-In-First-Out, which is the defining behaviour of a queue.