leetcode 191

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.

求出输入整数的32位中有多少位值为1.

代码如下：

 class Solution {
 public:
     int hammingWeight(uint32_t n) {
         unsigned pos =  << ;
         int count = ;
         while(pos)
         {
             if(pos & n)
             {
                 count++;
             }
             pos >>= ;
         }
         return count;
     }
 };