leetcode-191-number of 1 bits

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.

写一个函数，返回某一数字二进制表示中1出现的次数

利用位运算中&操作符号，和指定数的每一位都单独&一次，如果是1，则会返回1，再使用一个计数器实现统计。

class Solution {
    public:
        int hammingWeight(uint32_t n) {
            int count=0;
            for(int i=0;i<32;i++)
                if(n&1<<i) count++;

            return count;

    }
};