TheAlgorithms-Python

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def is_even(number: int) -> bool:
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    """
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    return true if the input integer is even
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    Explanation: Lets take a look at the following decimal to binary conversions
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    2 => 10
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    14 => 1110
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    100 => 1100100
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    3 => 11
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    13 => 1101
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    101 => 1100101
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    from the above examples we can observe that
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    for all the odd integers there is always 1 set bit at the end
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    also, 1 in binary can be represented as 001, 00001, or 0000001
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    so for any odd integer n => n&1 is always equals 1 else the integer is even
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    >>> is_even(1)
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    False
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    >>> is_even(4)
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    True
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    >>> is_even(9)
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    False
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    >>> is_even(15)
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    False
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    >>> is_even(40)
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    True
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    >>> is_even(100)
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    True
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    >>> is_even(101)
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    False
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    """
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    return number & 1 == 0
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if __name__ == "__main__":
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    import doctest
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    doctest.testmod()
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