2019.9.23-希尔排序实现代码

# coding:utf-8

def shell_sort(alist):
"""希尓排序"""
# n = 9
n = len(alist)
# gap = 4
gap = n // 2

# i = gap
# for i in range(gap, n):
# i = [gap, gap+1, gap+2, gap+3... n-1]
# while:
# if alist[i] < alist[i-gap]:
# alist[i], alist[i-gap] = alist[i-gap], alist[i]

# gap變化到0之前，插入算法執行的次數
while gap > 0:
# 插入算法， 與普通的插入算法的區別就是gap步長
for j in range(gap, n):
# j = [gap, gap+1, gap+2, gap+3, ..., n-1]
i = j
while i > 0:
if alist[i] < alist[i-1]:
alist[i], alist[i-gap] = alist[i-gap], alist[i]
i -= gap
else:
break

# 縮短ga步長
gap //= 2

if __name__ == "__main__":
li = [54, 26, 93, 17, 77, 31, 44, 55, 20]
print(li)
shell_sort(li)
print(li)

 

 

 

 

执行结果