백준 1927 c++ [최소힙]

#include <iostream>
#include <vector>
#include <algorithm>
#include <iostream>
#include <set>
#include <queue>

using namespace std;



int main()
{	
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);

	int n, x;
	priority_queue<int,vector<int>,greater<int>>pq;	//오름차순, 작은숫자가 먼저
	//priority_queue<int>pq;	//내림차순, 큰숫자가 먼저

	cin >> n;
	
	for (int i = 0; i < n; i++)
	{
		cin >> x;

		if (x == 0)
		{
			if (!pq.empty())
			{
				cout << pq.top() << '\n';
				pq.pop();
			}
			else
				cout << "0" << '\n';
		}
		else
		{
			pq.push(x);
		}
	}
	




	return 0;
}