LeetCode OJ：Number of 1 Bits（比特1的位数）

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.

计算一个数字的二进制表示中含有的bit1的个数，简单的右移而已，代码如下所示：

 1 class Solution {
 2 public:
 3     int hammingWeight(uint32_t n) {
 4         if(n == 0) return 0;
 5         int ret = 0;
 6         while(n != 0){
 7             if(n & 1 == 1){
 8                 ret++;
 9             }
10             n >>= 1;
11         }
12         return ret;
13     }
14 };