[programmers] 이중 우선순위 큐

programmers.co.kr/learn/courses/30/lessons/42628

코딩테스트 연습 - 이중우선순위큐

import java.util.*;

class Solution {
    public int[] solution(String[] operations) {
        PriorityQueue<Integer> minHeap = new PriorityQueue<>();
		PriorityQueue<Integer> maxHeap = new PriorityQueue<>(Collections.reverseOrder());
		for(String op : operations) {
			int val = Integer.parseInt(op.substring(1).trim());
			if(op.charAt(0) == 'I') { // 숫자 삽입
				minHeap.offer(val);
				maxHeap.offer(val);
			} else if(op.charAt(0) == 'D') { // 숫자 삭제
				if(val == 1) {	// 최대값 삭제
					if(!maxHeap.isEmpty()) {
						minHeap.remove(maxHeap.poll());
					}
				} else if(val == -1) {	// 최소값 삭제
					if(!minHeap.isEmpty()){
						maxHeap.remove(minHeap.poll());
					}
				}
			}
		}
		int[] ans = new int[2];
		if(!maxHeap.isEmpty() || !minHeap.isEmpty()) {
			ans[0] = maxHeap.peek();
			ans[1] = minHeap.peek();
		}
        return ans;
    }
}