#1845
Seat Reservation Manager
medium · 67.1% accepted · 1,477 likes · top 73%
design · heap (priority queue)
Description
Design a system that manages the reservation state of n seats that are numbered from 1 to n.
Implement the SeatManager class:
- SeatManager(int n) Initializes a SeatManager object that will manage n seats numbered from 1 to n. All seats are initially available.
- int reserve() Fetches the smallest-numbered unreserved seat, reserves it, and returns its number.
- void unreserve(int seatNumber) Unreserves the seat with the given seatNumber.
Example 1:
Input
["SeatManager", "reserve", "reserve", "unreserve", "reserve", "reserve", "reserve", "reserve", "unreserve"]
[[5], [], [], [2], [], [], [], [], [5]]
Output
[null, 1, 2, null, 2, 3, 4, 5, null]
Example 2:
Explanation
SeatManager seatManager = new SeatManager(5); // Initializes a SeatManager with 5 seats.
seatManager.reserve(); // All seats are available, so return the lowest numbered seat, which is 1.
seatManager.reserve(); // The available seats are [2,3,4,5], so return the lowest of them, which is 2.
seatManager.unreserve(2); // Unreserve seat 2, so now the available seats are [2,3,4,5].
seatManager.reserve(); // The available seats are [2,3,4,5], so return the lowest of them, which is 2.
seatManager.reserve(); // The available seats are [3,4,5], so return the lowest of them, which is 3.
seatManager.reserve(); // The available seats are [4,5], so return the lowest of them, which is 4.
seatManager.reserve(); // The only available seat is seat 5, so return 5.
seatManager.unreserve(5); // Unreserve seat 5, so now the available seats are [5].
Solution