LeetCode 191：number of one bits

题目就是：

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.

这就是考十进制转二进制的题，学到了#include <cstdin>这个头文件，还有简单的转换算法，算法里边数据类型，别随手定义成了int!!!

class Solution {
public:
    int hammingWeight(uint32_t n) 
    {
        uint32_t iRet = 0;
        uint32_t flag = 1;
        uint32_t iRes = n;
        uint32_t iLeft = 0;
        while(flag != 0)
        {
            flag = iRes / 2;
            iLeft = iRes - flag * 2;
            if(iLeft == 1)
            {
                ++iRet;
            }
            iRes = flag;
        }
        return iRet;
    }
};

写的不好，但多code多学习总是有用。