leetcode 剑指 Offer 40. 最小的k个数

class Solution {
    public int[] getLeastNumbers(int[] arr, int k) {
        int[] ints = new int[k];

        if(k==0 || arr==null || arr.length < k )
            return ints;


        PriorityQueue<Integer> queue = new PriorityQueue<>(k,Collections.reverseOrder());


        for (int i = 0; i < arr.length; i++) {

            if(i<k){
                queue.offer(arr[i]);
            }else{

                if(queue.peek()>arr[i]){
                    queue.poll();
                    queue.offer(arr[i]);
                }
            }

        }


        for (int i = 0; i < k; i++) {
            ints[i] = queue.poll();
        }

        return ints;
    }
}