下述python代码实现了快速排序算法，最差情况时间复杂度是（ ）。

def partition(arr, low, high):
    i = low
    j = high
    pivot = arr[low]

    while i < j:
        while i < j and arr[j] >= pivot:
            j -= 1
        while i < j and arr[i] <= pivot:
            i += 1
        if i < j:
            arr[i], arr[j] = arr[j], arr[i]

    arr[i], arr[low] = arr[low], arr[i]
    return i

def quick_sort(arr, low, high):
    if low >= high:
        return

    p = partition(arr, low, high)
    quick_sort(arr, low, p - 1)
    quick_sort(arr, p + 1, high)

def quick_sort_wrapper(arr):
    if not arr:
        return []
    quick_sort(arr, 0, len(arr) - 1)
    return arr