AcWing 每日一题春季（九）LeetCode 191. 位1的个数（树状数组lowbit）

class Solution {
public:
    long long int lb(long long int x){
        return x&-x;
    }
    int hammingWeight(uint32_t n) {
        long long int res=0;
        while(n){
            n-=lb(n);
            res++;
        }
        return res;
    }
};