欧拉计划(python) problem 28

时间：2015-02-01 16:13:49 收藏：0 阅读：232

Number spiral diagonals

Starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral is formed as follows:

21 22 23 24 25
20 7  8 9 10
19 6 1  2 11
18 5  4 3 12
17 16 15 14 13

It can be verified that the sum of the numbers on the diagonals is 101.

What is the sum of the numbers on the diagonals in a 1001 by 1001 spiral formed in the same way?

Go to the thread for problem 28 in the forum.

python code:

k=1
step=0
result=1
for i in range(3,1003,2):
step+=2
for j in range(0,4):
k+=step
result+=k
print(result)

time <1s