class Solution {
    public int[] getLeastNumbers(int[] arr, int k) {
        PriorityQueue<Integer> pq = new PriorityQueue<>((a, b) -> Integer.compare(b, a));
        for(int num : arr){
            pq.offer(num);
            if(pq.size() > k) pq.poll();
        }
        return pq.stream().mapToInt(x -> x).toArray();
    }
}

class Solution {
    public int[] getLeastNumbers(int[] arr, int k) {
        if(k == 0) return new int[0];
        quickSort(arr, 0, arr.length - 1, k - 1);
        return Arrays.copyOf(arr, k);
    }

    int quickSort(int[] arr, int l, int r, int k){
        if(l >= r) return arr[k];

        int i = l - 1, j = r + 1, x = arr[l + r >> 1];
        while(i < j){
            while(arr[++i] < x);
            while(arr[--j] > x);
            if(i < j){
                int tmp = arr[i];
                arr[i] = arr[j];
                arr[j] = tmp;
            }
        }

        if(k <= j) return quickSort(arr, l, j, k);
        else return quickSort(arr, j + 1, r, k);
    }
}