191. Number of 1 Bits

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

把末尾的位摘下来直接累加就行，直到原数字因为右移操作变为0。