Number of 1 Bits

【问题描述】

Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the ).

For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011, so the function should return 3.

【解决方案】

int hammingWeight(uint32_t n) {
    int count;

    for(count = 0; n != 0; n >>= 1)
    {
        if( n & 1 != 0)
            count++;
    }

    return count;
}