JZ29 最小的 K 个数

https://www.nowcoder.com/practice/6a296eb82cf844ca8539b57c23e6e9bf

import java.util.ArrayList;
import java.util.PriorityQueue;

public class Solution {
    public ArrayList<Integer> GetLeastNumbers_Solution(int [] input, int k) {
        ArrayList<Integer> result = new ArrayList<Integer>();

        if(k > input.length || k == 0){
            return result;
        }
        
        PriorityQueue<Integer> maxHeap = new PriorityQueue<>(k,  (o1 ,o2) -> o2 - o1);

        for (int i = 0; i < input.length; i++) {
            if (maxHeap.size() != k) {
                maxHeap.offer(input[i]);
            } else if (maxHeap.peek() > input[i]) {
                maxHeap.poll();
                maxHeap.offer(input[i]);
            }
        }
        
        for (Integer i : maxHeap) {
            result.add(i);
        }
        
        return result;
    }
}