1927번 (최소 힙)

나의 코드

import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] arr = new int[n];

        PriorityQueue<Integer> pq = new PriorityQueue<>();

        for (int i = 0; i < n; i++) {
            int x = sc.nextInt();

            if (x == 0) {
                if (pq.isEmpty()) {
                    System.out.println("0");
                } else {
                    System.out.println(pq.poll());
                }
            } else {
                pq.add(x);
            }
        }
    }
}