l1=[i for i in range(1,10)]
# l1=1,2,3,4,5,6,7,8,9,10,11,12,13,14
# # start_index=0
# # end_index=len(l1)-1
# while start_index<=end_index:
# # mid_index=(start_index+end_index)//2
# if l1[mid_index]==77:
# print()
# break
# elif l1[mid_index]>77:
# end_index=mid_index-1
# else:
# start_idex=mid_index+1
# print(找到了) 找到就返回index，否侧返回-1
判断l1[mid_index]是不是你要找的
# l = [77,88,99,66,55]
# sum_num = 0
# for i in l:
# sum_num += i
# print(sum_num//5)
#
# print(sum(l))
# print(max(l))
# sum_num = 0
# for i in range(1,101):
# sum_num += i
# l=[55, 66, 77, 88, 99]
# max_num=l[0]
# i=1
# while i<len(l):
# i+=1
# print(max_num)
# l=[55, 66, 77, 88, 99]
# min_num=l[0]
# i=1
# while i<len(l):
# i+=1
# print(min_num)
冒泡排序
# for j in range(len(l1)-1):
# for i in range(len(l1)-1-j):
# if l1[i]>l1[i+1]:
# l1[i],l1[i+1]=l1[i+1],l1[i]