Euler Project Problem #028

euler28.rb

# Solution to Project Euler's twenty-eighth problem
# http://projecteuler.net/index.php?section=problems&id=28
# Find the sum of the diagonals of a 1001 spiral grid.
def spiral_sum(number)
sum, n = 0, 0
(0..number).to_a.each do |x|
	n = 2*x + n
	sum = sum + n + 1
end
n = 0
(1..number).to_a.each do |x|
	if x.odd? then y = x + 1 else y = x end
	n = 2*y + n
	sum = sum + n + 1
end
return sum
end
number = 1000
sum = spiral_sum(number) 
p sum