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 r = 0;
        for(int i=0;i<32;i++){
            if(n & 0x01 == 1) r+=1;
            n = n >> 1;
        }
        return r;
    }
};