📚우선 순위 큐, 자료구조
https://www.acmicpc.net/problem/11279
우선 순위 큐를 사용 ( 최소 힙 구현 ) + Collections.reverseOrder() 로 역순으로 저장
package com.example.baekjoon;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Collections;
import java.util.PriorityQueue;
public class Main {
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
PriorityQueue<Integer> q = new PriorityQueue<>(Collections.reverseOrder());
int t = Integer.parseInt(br.readLine());
for (int i = 0; i < t; i++) {
int n = Integer.parseInt(br.readLine());
if (n != 0) {
q.add(n);
} else {
if (q.isEmpty()) {
System.out.println(0);
} else {
System.out.println(q.poll());
}
}
}
}
}