注：1到3是特殊情况
class Solution():
def cutrope(self,k):
A = [0]*(k+1)
A[1] = 1
A[2] = 2
A[3] = 3
if k <2:
return 0
if k ==2:
return 1
if k ==3:
return 2
else:
for i in range(4,k+1):
for j in range(1,int(i/2)+2):
A[i] = max(A[i],A[j]*A[i-j])
return A[k]
#test
s = Solution()
print(s.cutrope(8))