Interview Question for Software Engineer Intern - Arabic Language - Zurich at Google:

My first idea to do this is something like:

int hamming(int myNumber)
{
    int counter = 0;
    int newValue = myNumber;
    while (newValue != 0)
    {
        newValue = (newValue >> 1);
        if (newValue & 0x01 == 0x01)
        {
            counter++;
        }
    }
    return counter;
}

Assuming that we have enough memory, the best simpliest way to improve it is to do something like that:

static unsigned char wordbits[65536] = { bitcounts of ints between 0 and 65535 };
int hamming(int myNumber)
{
    return( wordbits[myNumber&0xFFFF] + wordbits[myNumber>>16] );
}