[BOJ] 11279 최대 힙 (JAVA)

https://www.acmicpc.net/problem/11279

11279번: 최대 힙

Priority Queue를 이용할 때 내림차순 정렬을 하기 위해 Comparator를 사용했습니다. 

 

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Comparator;
import java.util.PriorityQueue;

public class Main {
	
    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    static StringBuilder sb = new StringBuilder();

    public static void main(String[] args) throws Exception {

        PriorityQueue<Integer> pq = new PriorityQueue<>(new Comparator<Integer>() {
            @Override
            public int compare(Integer o1, Integer o2) {
                return o2 - o1;
            }
        });
        int N = Integer.parseInt(br.readLine());
        for (int i = 0; i < N; i++) {

            int a = Integer.parseInt(br.readLine());

            if(a == 0) {
                if(pq.isEmpty()) sb.append("0\n");
                else sb.append(pq.poll() + "\n");
            } else pq.offer(a);

        }

        System.out.print(sb.toString());

    }

}