2019.9.23-插入排序2

# coding:utf-8

def insert_sort(alist):
"""插入排序"""
n = len(alist)
for j in range(1, n):
# j = [1, 2, 3, n-1]
# i 代表內層循環起始值
i = j
# 執行從右邊的無序序列中取出第一個元素，即i位置的元素，然後將其插入到前面的正確位置中
while i > 0:
if alist[i] < alist[i-1]:
alist[i], alist[i-1] = alist[i-1], alist[i]
i -= 1
else:
break
if __name__ == "__main__":
li = [54, 26, 93, 17, 77, 31, 44, 55, 20]
print(li)
insert_sort(li)
print(li)