题目描述：

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.

代码实现：

class Solution {
public:
    int hammingWeight(uint32_t n) {
        int sum=0;
        while(n>0){
            if(n&1==1){
                sum++;
            }
            n=n>>1;
        }
        return sum;
    }
};