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38 lines
834 B
Python
38 lines
834 B
Python
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 deicmal 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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