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Satwik Mohantypre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>Christian Clauss* Fix zero input bug in binary_count_trailing_zeros * [pre-commit.ci] auto fixes from pre-commit.com hooks for more information, see https://pre-commit.ci --------- Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com> Co-authored-by: Christian Clauss <cclauss@me.com>
56 lines
1.4 KiB
Python
56 lines
1.4 KiB
Python
from math import log2
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def binary_count_trailing_zeros(a: int) -> int:
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"""
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Take in 1 integer, return the number of trailing zeros in binary representation.
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>>> binary_count_trailing_zeros(25)
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0
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>>> binary_count_trailing_zeros(36)
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2
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>>> binary_count_trailing_zeros(16)
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4
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>>> binary_count_trailing_zeros(58)
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1
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>>> binary_count_trailing_zeros(4294967296)
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32
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>>> binary_count_trailing_zeros(0)
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Traceback (most recent call last):
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...
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ValueError: Trailing zeros for 0 are undefined
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>>> binary_count_trailing_zeros(-10)
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Traceback (most recent call last):
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...
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ValueError: Input value must be a positive integer
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>>> binary_count_trailing_zeros(0.8)
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Traceback (most recent call last):
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...
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TypeError: Input value must be an integer
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>>> binary_count_trailing_zeros("0")
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Traceback (most recent call last):
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...
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TypeError: Input value must be an integer
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"""
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# Type check
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if not isinstance(a, int):
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raise TypeError("Input value must be an integer")
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# Edge case: zero
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if a == 0:
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raise ValueError("Trailing zeros for 0 are undefined")
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# Negative numbers not allowed
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if a < 0:
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raise ValueError("Input value must be a positive integer")
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# Core logic
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return int(log2(a & -a))
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if __name__ == "__main__":
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import doctest
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doctest.testmod()
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