Leetcode 476. Number Complement

Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.

Note:

1. The given integer is guaranteed to fit within the range of a 32-bit signed integer.
2. You could assume no leading zero bit in the integer’s binary representation.

 

Example 1:

Input: 5
Output: 2
Explanation: The binary representation of 5 is 101 (no leading zero bits), and its complement is 010. So you need to output 2.

 

Example 2:

Input: 1
Output: 0
Explanation: The binary representation of 1 is 1 (no leading zero bits), and its complement is 0. So you need to output 0.

def findComplement(self, num: int) -> int:
        bits_width = 0
        copy_of_num = num
        while copy_of_num != 0:
            bits_width += 1
            copy_of_num >>= 1
        for i in range(bits_width):
            num ^= (1 << i)
        return num