1009. Complement of Base 10 Integer

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 n, return its complement.

Example 1:

Input: n = 5
Output: 2
Explanation: 5 is "101" in binary, with complement "010" in binary, which is 2 in base-10.

Example 2:

Input: n = 7
Output: 0
Explanation: 7 is "111" in binary, with complement "000" in binary, which is 0 in base-10.

Example 3:

Input: n = 10
Output: 5
Explanation: 10 is "1010" in binary, with complement "0101" in binary, which is 5 in base-10.

Constraints:

• 0 <= n < 109

Note: This question is the same as 476: https://leetcode.com/problems/number-complement/

class Solution:
    def bitwiseComplement(self, n: int) -> int:
        # Same as PB 476 : https://leetcode.com/problems/number-complement/
        if n == 0:
            return 1
        bit = 1
        while bit <= n:
            bit = bit << 1
        return (bit-1) ^ n