euler/python/e028.py

32 lines
766 B
Python

"""What is the sum of both diagonals in a 1001 by 1001 spiral?
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?
"""
def main():
n = 1
total = 1
size = 1
MAX_SIZE = 1001
while size <= MAX_SIZE:
for i in range(4):
n = n + (size - 1)
if n > 1:
total = total + n
size = size + 2
print 'Total:', total
if __name__ == '__main__':
main()