def partition(arr, low, high):
    pivot = arr[high]
    i = low - 1

    for j in range(low, high):
        _________________________________

    arr[i + 1], arr[high] = arr[high], arr[i + 1]
    return i + 1

def quick_sort(arr, low, high):
    if low < high:
        pi = partition(arr, low, high)
        quick_sort(arr, low, pi - 1)
        quick_sort(arr, pi + 1, high)