def main():
"""Main program."""
# This is my first, brute force solution.
# The spiral of the required dimensions is
# represented by a matrix and the diagonal
# sum calculated by visiting each cell in
# the two diagonals.
answer = 0
start = time.time()
spiral = spirals.build_spiral(1001, 1001)
answer = spirals.diagonal_sum(spiral)
end = time.time()
print("The answer is %d" % answer)
print("%f seconds elapsed." % (end - start))
# After verifying the above solution, I
# ran matrices 3x3, 5x5, 7x7, and 9x9.
# I noticed the patter in the corners
# and so I came up with a second solution.
# I used the data from OEIS sequence A114254
# to verify that this method of calculating
# the diagonal sums is correct.
start = time.time()
answer = spirals.calculate_diagonal_sum(1001)
end = time.time()
print("The answer is %d" % answer)
print("%f seconds elapsed." % (end - start))
import pyperclip
pyperclip.copy(str(answer))
print("The answer has been placed in the clipboard.")
def test_calculate_diagonal_sum(self):
"""Test calculate_diagonal_sum()"""
a114254 = [1, 25, 101, 261, 537, 961, 1565, 2381, 3441, 4777, \
6421, 8405, 10761, 13521, 16717, 20381, 24545, \
29241, 34501, 40357, 46841, 53985, 61821, 70381, \
79697, 89801, 100725, 112501, 125161, 138737, \
153261, 168765, 185281, 202841, 221477, 241221]
for index, value in enumerate(a114254):
dim = index * 2 + 1
self.assertEquals(value, spirals.calculate_diagonal_sum(dim))
