How do I count the number of zero bits in an integer?

Question

How would i go about finding the number of \'zero\' bits in C++. Suppose I have an integer;

int value = 276; 

For which I have the bits 100010

Answer 1

According to me , the simplest way to get the zero bit count in a positive integer is the following piece of code.

int get_zero_bit_count(int num)
{
    int cnt = 0;

    while(num > 0)
        {
            int and_num = num & 1;

            if (and_num != num) cnt++;

            num >>= 1; 
        }

        return cnt;
    }

This piece of code is easy to understand and is selp explainatory . This works well for positive integers.