算法1

题意：计算二进制数中1的个数
思路：lowbit()常用函数

C++ 代码

class Solution {
public:
    uint32_t lowbit(uint32_t x)
    {
      return x &-x;  //返回末尾1
    }
    int hammingWeight(uint32_t n) {
        int cnt=0;
        while(n)n-=lowbit( n),cnt++;
        return cnt;
    }
};