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SARATHI-78SARATHI-78Christian Clausspre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>* Add evil_number algorithm in maths/special_numbers * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci --------- Co-authored-by: SARATHI-78 <sundarasarathi78@gmail.com> Co-authored-by: Christian Clauss <cclauss@me.com> Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
68 lines
1.6 KiB
Python
68 lines
1.6 KiB
Python
"""
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== Evil Number ==
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An evil number is a non-negative integer that has an even number of 1s in its
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binary expansion. Numbers that are not evil are called odious numbers.
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Examples of evil numbers: 0, 3, 5, 6, 9, 10, 12, 15, 17, 18, 20, 23, 24, 27, ...
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Reference: https://en.wikipedia.org/wiki/Evil_number
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"""
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def is_evil_number(number: int) -> bool:
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"""
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Check if a given number is an evil number.
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A non-negative integer is evil if the sum of its binary digits (its Hamming weight)
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is even.
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:param number: A non-negative integer.
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:return: True if number is an evil number, False otherwise.
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>>> is_evil_number(0)
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True
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>>> is_evil_number(3)
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True
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>>> is_evil_number(5)
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True
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>>> is_evil_number(6)
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True
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>>> is_evil_number(9)
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True
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>>> is_evil_number(1)
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False
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>>> is_evil_number(2)
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False
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>>> is_evil_number(4)
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False
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>>> is_evil_number(7)
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False
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>>> is_evil_number(8)
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False
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>>> is_evil_number(-1)
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Traceback (most recent call last):
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...
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ValueError: Input must be a non-negative integer
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>>> is_evil_number(5.5)
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Traceback (most recent call last):
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...
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TypeError: Input must be an integer
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"""
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if not isinstance(number, int):
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raise TypeError("Input must be an integer")
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if number < 0:
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raise ValueError("Input must be a non-negative integer")
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count = 0
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temp = number
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while temp > 0:
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if temp % 2 == 1:
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count += 1
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temp = temp // 2
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return count % 2 == 0
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if __name__ == "__main__":
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import doctest
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doctest.testmod()
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