def shell_sort(alist):
n = len(alist)
# 初始步长
gap = round(n / 2)
while gap > 0:
# 按步长进行插入排序
for i in range(gap, n):
j = i
# 插入排序
while j>=gap and alist[j-gap] > alist[j]:
alist[j-gap], alist[j] = alist[j], alist[j-gap]
j -= gap
# 得到新的步长
gap = round(gap / 2)
alist = [54,26,93,17,77,31,44,55,20,99,64]
shell_sort(alist)
print(alist)