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.

 

 

public class Solution {
    public int findComplement(int num) {
        int result = 0;
        int i = 0;
        while (num > 0) {
            int temp = (num & 1) ^ 1;
            num >>= 1;
            result += temp << i;
            i++;
        }
        return result;
    }
}