백준11279 최대힙

힙

11279번: 최대 힙Baekjoon Online Judge

Solution 1. 미리 구현된 PriorityQueue 자료형 사용

package practice.algorithm.stackqueue;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.PriorityQueue;
import java.util.Collections;

/**
 * https://www.acmicpc.net/problem/11279
 * 26212 kb / 336 ms
 * 최대 힙
 * - 미리 구현된 PriorityQueue 자료형을 사용한다.
 * */
public class Bj11279 {
    private static final PriorityQueue<Integer> maxHeap = new PriorityQueue<>(Collections.reverseOrder());

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());

        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < n; i++) {
            int x = Integer.parseInt(br.readLine());
            int result = maxHeap(x);
            if (result >=0 ) {
                sb.append(result).append("\n");
            }
        }

        System.out.println(sb);
    }

    private static int maxHeap(int x) {
        if (x == 0) {
            if (maxHeap.isEmpty()) {
                return 0;
            }

            return maxHeap.poll();
        }

        maxHeap.offer(x);
        return -1;
    }
}