476. Number Complement

Easy

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The complement of an integer is the integer you get when you flip all the 0's to 1's and all the 1's to 0's in its binary representation.

• For example, The integer 5 is "101" in binary and its complement is "010" which is the integer 2.

Given an integer num, return its complement.

Example 1:

Input: num = 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: num = 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.

Constraints:

• 1 <= num < 231

Note: This question is the same as 1009: https://leetcode.com/problems/complement-of-base-10-integer/

class Solution:
    def findComplement(self, num: int) -> int:
        s = bin(num).replace('0b','')
        power = 0
        total = 0
        for char in s[::-1]:
            if char == '0':
                total += pow(2, power)
            power += 1
        return total