题目
Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.
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
class Solution:
def findComplement(self, num: int) -> int:
x = 1
while x <= num:
x <<= 1
return (x - 1) ^ num
