19 lines
418 B
Python
19 lines
418 B
Python
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# Time: O(N) where N is number of bits
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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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cn, bit = n, 1
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while n > 0:
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# XOR 1 can be used to flip bit.
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# 0 XOR 1 = 1
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# 1 XOR 1 = 0
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cn = cn ^ bit
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bit = bit << 1
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n = n >> 1
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return cn
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