476-Number-Complement.cpp

476. Number Complement

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

Note:
The given integer is guaranteed to fit within the range of a 32-bit signed integer.
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.





class Solution {
public:
    int findComplement(int num) {
        int sum=0,val=1;
        while(num>0){
            if(num%2==0){
                sum+=val;
            }
            val *= 2;
            num/=2;
        }
        return sum;
    }
};