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;
}
};