###此题与476 Number Complement 完全相同
题目
Every non-negative integer N has a binary representation. For example, 5 can be represented as “101” in binary, 11 as “1011” in binary, and so on. Note that except for N = 0, there are no leading zeroes in any binary representation.
The complement of a binary representation is the number in binary you get when changing every 1 to a 0 and 0 to a 1. For example, the complement of “101” in binary is “010” in binary.
For a given number N in base-10, return the complement of it’s binary representation as a base-10 integer.
解题思路
对应一个n位数m，最后的结果为(2**n - 1) ^ m （2的n次幂减一的结果异或m）
代码
python
class Solution:
def bitwiseComplement(self, N: int) -> int:
if N == 0:
return 1
x = 1
while x <= N:
x <<= 1
return (x - 1) ^ N
