最小的k个数

使用java中的优先队列：

public ArrayList<Integer> GetLeastNumbers_Solution(int [] input, int k) {
        ArrayList<Integer> result = new ArrayList<>();
        int length=input.length;
        if(k > length || k == 0){
           return result;
        }
        PriorityQueue<Integer> priority = new PriorityQueue<>(k, new Comparator<Integer>() {

            @Override
            public int compare(Integer o1, Integer o2) {
                return o2.compareTo(o1);
            }
        });
        for(int i=0;i<length;i++) {
            if(priority.size()!=k) {
                priority.offer(input[i]);
            }
            else if(priority.peek()>input[i])
            {
                int temp=priority.poll();
                if(input[i]<temp) {
                    priority.offer(input[i]);
                }
            }
        }
        for(Integer i:priority) {
            result.add(i);
        }
        return result;
    }