Implement Seat Reservation Manager in Python



Suppose we have to design a system that manages the reservation state of n seats. The seats are numbered from 1 to n. So we have to implement the SeatReserveManager class, with these functions −

  • Constructor that takes n as input and initializes the object that will manage n seats numbered from 1 to n. Initially all seats are available.

  • reserve(), this will fetch the smallest-numbered unreserved seat, then reserves it, and returns its number.

  • unreserve(seatNumber), this will unreserve one reserved seat with the given seatNumber.

So, if the input is like

  • obj = SeatReserveManager(7)

  • obj.reserve()

  • obj.reserve()

  • obj.reserve()

  • obj.unreserve(2)

  • obj.unreserve(5)

  • obj.reserve()

  • obj.reserve()

then the output will be 1, 2, 3, 2, 5, initially reserve three seats 1, 2, 3, then unreserved 2 and 5 but 5 is not reserved yet, then reserve 5 next.

To solve this, we will follow these steps −

  • Define the Constuctor() . This will take n

  • current_seat := 0

  • empty_seats := a new list

  • Define a function reserve() . This will take

  • if length of empty_seats > 0, then

    • s := minimum of empty_seats

    • delete s from empty_seats

    • return s

  • current_seat := current_seat + 1

  • return current_seat

  • Define a function unreserve(). This will take seatNumber

  • insert seatNumber at the end of empty_seats

Example

Let us see the following implementation to get better understanding −

Open Compiler
class SeatReserveManager: def __init__(self, n): self.current_seat = 0 self.empty_seats = [] def reserve(self): if len(self.empty_seats) > 0: s = min(self.empty_seats) self.empty_seats.remove(s) return s self.current_seat += 1 return self.current_seat def unreserve(self, seatNumber): self.empty_seats.append(seatNumber) obj = SeatReserveManager(7) print(obj.reserve()) print(obj.reserve()) print(obj.reserve()) obj.unreserve(2) obj.unreserve(5) print(obj.reserve()) print(obj.reserve())

Input

obj = SeatReserveManager(7) print(obj.reserve()) print(obj.reserve()) print(obj.reserve()) obj.unreserve(2) obj.unreserve(5) print(obj.reserve()) print(obj.reserve())

Output

1 2 3 2 5
Updated on: 2021-10-08T07:03:49+05:30

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