18 lines
496 B
Python
18 lines
496 B
Python
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class Solution:
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def bitwiseComplement(self, n: int) -> int:
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if n == 0:
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return 1
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mask = n
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# Create mask of length matching num of bits
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# in n (taken from Hacker's Delight, Figure 3-1)
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mask |= mask >> 1 # \
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mask |= mask >> 2 # \
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mask |= mask >> 4 # |> Totalling 31 bits
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mask |= mask >> 8 # /
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mask |= mask >> 16 # /
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# XOR 1 will flip the bit
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return n ^ mask
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