座位预约管理系统

/*
 * This Java solution also uses a PriorityQueue but with more functional programming aspects.
 * Since PriorityQueue doesn't have direct stream manipulation, the code retains the same logic 
 * but shows how functional-style comments could apply if operations were stream-capable.
 * For example, adding seats in the constructor can be seen as a map operation.
 */
import java.util.PriorityQueue;

public class SeatManager {
    private PriorityQueue<Integer> availableSeats;

    public SeatManager(int n) {
        availableSeats = new PriorityQueue<>();
        // Stream-like initialization (not actual streams)
        for (int i = 1; i <= n; i++) {
            availableSeats.add(i);
        }
    }

    public int reserve() {
        return availableSeats.poll();
    }

    public void unreserve(int seatNumber) {
        availableSeats.add(seatNumber);
    }
}