Number of 1 Bits

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

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

Solution:

    int hammingWeight(uint32_t n) {
        int co = 0;
        while(n != 0){
            if (n&1 == 1) co++;
            n >>= 1;
        }
        return co;
    }

int hammingWeight(uint32_t n) {
    int count = 0;
    while (n > 0) {
        count++;
        n &= n-1;
    }
    return count;
}