测试文件已写

1.检测数字序列两边相加是否相等，相等返回中间的数，否则返回-1

a=[1,2,3,4,5]   return -1

b=[7,8,5,7,,8]   return 5

1、

a=[1,2,3,4,5]

b=[7,8,5,8,7]

def find(arr):

      for i,key in enumerate(arr):

               r=0

               l=0

               for x in arr[i+1:]:#序列长度为n，取序列右边的n—(i+1)个数

                       r+=x

               for x in arr[:i]:

                       l +=x

               if(r==l):

                       return arr[i]

                       break

        return -1 #print(i,key) print(find(b))

print(find([7,8,5,8,7]))

2，十进制转二进制

def test(request): 

       sum = 5615

       temp = []

       b_sum = ''

       while sum>0:

               temp.append(sum%2)

               sum = int(sum/2) 

        while temp: 

        b_sum =b_sum + str(temp.pop())

        return HttpResponse(b_sum)