希尔排序--python

 import random
 import time

 # 插入排序
 def insertion_sort(arr, step):
     for i in range(step, len(arr)):
         for j in range(i, step - 1, -step):
             if arr[j] < arr[j-step]:
                 arr[j], arr[j-step] = arr[j-step], arr[j]
             else:
                 break

 # 希尔排序：插入排序算法的优化算法
 def shell_sort(arr):
     length = len(arr)
     step = 1

     while step < length // 3:
         step = 3 * step + 1

     while step >= 1:
         insertion_sort(arr, step)
         step = step // 3

 if __name__ == '__main__':
     arr = [random.randint(0, 1000000) for _ in range(5000)]
     print('待排序数组大小:', len(arr))
     start = time.time()
     shell_sort(arr)
     end = time.time()
     print('用时:', end - start)