maths.special_numbers.evil_number
=================================

.. py:module:: maths.special_numbers.evil_number

.. autoapi-nested-parse::

   == Evil Number ==
   An evil number is a non-negative integer that has an even number of 1s in its
   binary expansion. Numbers that are not evil are called odious numbers.

   Examples of evil numbers: 0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, ...
   Reference: https://en.wikipedia.org/wiki/Evil_number



Functions
---------

.. autoapisummary::

   maths.special_numbers.evil_number.is_evil_number


Module Contents
---------------

.. py:function:: is_evil_number(number: int) -> bool

   Check if a given number is an evil number.

   A non-negative integer is evil if the sum of its binary digits (its Hamming weight)
   is even.

   :param number: A non-negative integer.
   :return: True if number is an evil number, False otherwise.

   >>> is_evil_number(0)
   True
   >>> is_evil_number(3)
   True
   >>> is_evil_number(5)
   True
   >>> is_evil_number(6)
   True
   >>> is_evil_number(9)
   True
   >>> is_evil_number(1)
   False
   >>> is_evil_number(2)
   False
   >>> is_evil_number(4)
   False
   >>> is_evil_number(7)
   False
   >>> is_evil_number(8)
   False
   >>> is_evil_number(-1)
   Traceback (most recent call last):
       ...
   ValueError: Input must be a non-negative integer
   >>> is_evil_number(5.5)
   Traceback (most recent call last):
       ...
   TypeError: Input must be an integer