leetcode-面试题40

class Solution {
    public int[] getLeastNumbers(int[] arr, int k) {
        if (k == 0) {
            return new int[0];
        }
        Queue<Integer> heap = new PriorityQueue<>(k, (i1, i2) -> Integer.compare(i2, i1));

        for (int e : arr) {
            if (heap.isEmpty() || heap.size() < k || e < heap.peek()) {
                heap.offer(e);
            }
            if (heap.size() > k) {
                heap.poll(); 
            }
        }

        int[] res = new int[heap.size()];
        int j = 0;
        for (int e : heap) {
            res[j++] = e;
        }
        return res;
    }
}