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.

class Solution {

public:

    int hammingWeight(uint32_t n) {

        int ret = ;

        for (unsigned int i = ; i != ; i <<= ){

            if(n & ) ret++;

            n >>= ;

        }

        return ret;

    }

};