1009. Complement of Base 10 Integer

Complement of Base 10 Integer - LeetCode

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

476. Number Complement · Jiyu (yanjiyu.com) Only difference is here we need to handle 0.

• code

class Solution {
    public int bitwiseComplement(int n) {
        if (n == 0) return 1;
        int round = n, bit = 1;
        while (round != 0){
            n = n ^ bit;
            bit = bit << 1;
            round = round >> 1;
        }
        return n;
    }
}

• code

class Solution:
    def bitwiseComplement(self, n: int) -> int:
        if n == 0: return 1
        return (1 << n.bit_length()) - 1 - n