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* feat: Add twin prime algorithm * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci * fix: Fix broken import statement Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
46 lines
1.1 KiB
Python
46 lines
1.1 KiB
Python
"""
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== Twin Prime ==
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A number n+2 is said to be a Twin prime of number n if
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both n and n+2 are prime.
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Examples of Twin pairs: (3, 5), (5, 7), (11, 13), (17, 19), (29, 31), (41, 43), ...
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https://en.wikipedia.org/wiki/Twin_prime
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"""
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# Author : Akshay Dubey (https://github.com/itsAkshayDubey)
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from maths.prime_check import is_prime
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def twin_prime(number: int) -> int:
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"""
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# doctest: +NORMALIZE_WHITESPACE
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This functions takes an integer number as input.
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returns n+2 if n and n+2 are prime numbers and -1 otherwise.
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>>> twin_prime(3)
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5
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>>> twin_prime(4)
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-1
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>>> twin_prime(5)
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7
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>>> twin_prime(17)
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19
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>>> twin_prime(0)
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-1
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>>> twin_prime(6.0)
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Traceback (most recent call last):
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...
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TypeError: Input value of [number=6.0] must be an integer
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"""
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if not isinstance(number, int):
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raise TypeError(f"Input value of [number={number}] must be an integer")
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if is_prime(number) and is_prime(number + 2):
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return number + 2
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else:
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return -1
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if __name__ == "__main__":
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import doctest
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doctest.testmod()
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