nekedome / project-euler

solutions/problem6.py

"""
Project Euler Problem 6: Sum Square Difference
==============================================

.. module:: solutions.problem6
   :synopsis: My solution to problem #6.

The source code for this problem can be
`found here <https://bitbucket.org/nekedome/project-euler/src/master/solutions/problem6.py>`_.

Problem Statement
#################

The sum of the squares of the first ten natural numbers is,
    :math:`1^2 + 2^2 + \\dots + 10^2 = 385`

The square of the sum of the first ten natural numbers is,
    :math:`(1 + 2 + \\dots + 10)^2 = 55^2 = 3025`

Hence the difference between the sum of the squares of the first ten natural numbers and the square of the sum is

This line is too long as per the coding-style (113/100).

:math:`3025 - 385 = 2640`.

Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.

This line is too long as per the coding-style (118/100).

Solution Discussion
###################

Simply iteratively build and sum the components of the two sequences:

* sum of the squares
* square of the sums

for the natural numbers :math:`1,2,\\dots,100`

Return the absolute value of the difference of these two sums.

Solution Implementation
#######################

.. literalinclude:: ../../solutions/problem6.py
   :language: python
   :lines: 45-
"""

from math import fabs


def solve():
    """ Compute the answer to Project Euler's problem #6 """
    upper_bound = 100
    sum_of_squares = 0
    square_of_sums = 0
    for i in range(1, upper_bound + 1):
        sum_of_squares += i * i
        square_of_sums += i
    square_of_sums = square_of_sums * square_of_sums
    answer = int(fabs(square_of_sums - sum_of_squares))
    return answer


expected_answer = 25164150

The name expected_answer does not conform to the constant naming conventions ((([A-Z_][A-Z0-9_]*)|(__.*__))$).