题解 | #最小的K个数#

import java.util.*;

public class Solution {
    public ArrayList<Integer> GetLeastNumbers_Solution(int [] input, int k) {
        PriorityQueue<Integer> heap=new PriorityQueue<Integer>((o1,o2) -> {return o2-o1;});
        ArrayList<Integer> list = new ArrayList<Integer>();
        if(input.length==0||k==0){
            return list;
        }
        for(int i=0;i<k;i++){
            heap.add(input[i]);
        }
        int top1=heap.peek();
        for(int i=k;i<input.length;i++){
            int top=heap.peek();
            if(top>input[i]){
                heap.poll();
                heap.add(input[i]);
            }
        }
        for(int i=0;i<k;i++){
            list.add(heap.poll());
        }
        return list;
    }
}