冒泡算法

#列表元素两辆比较，大的值逐渐向后移动
# def sort(alist):
#     for i in range(len(alist)-1):
#         if alist[i]>alist[i+1]:
#             alist[i],alist[i+1]=alist[i+1],alist[i]
#     return alist
#
# alist=[1,3,5,2,6,9,8,7]
# print(sort(alist))

# [1, 3, 2, 5, 6, 8, 7, 9]

#逐渐将乱序序列的最大值找出放置在乱序序列的尾部
# def sort(alist):
#     for j in range(len(alist)-1):
#         for i in range(len(alist)-1-j):
#             if alist[i]>alist[i+1]:
#                 alist[i],alist[i+1]=alist[i+1],alist[i]
#     return alist
#
# alist=[1,3,5,2,6,9,8,7]
# print(sort(alist))

# [1, 2, 3, 5, 6, 7, 8, 9]

选择排序

#建乱序中的最大值找出，跟最后一个元素交换位置
# def sort(alist):
#     max_index=0 #最大值下标
#     for  i in range(1,len(alist)):
#         if alist[max_index]<alist[i]:
#             max_index=i
#     alist[len(alist)-1],alist[max_index]=alist[max_index],alist[len(alist)-1]
#     return alist
# alist=[3,8,5,7,6]
# print(sort(alist))