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.

Credits:

Special thanks to @ts for adding this problem and creating all test cases.

class Solution {
public:
int hammingWeight(uint32_t n) {
string s="";
while(n/2)
{
s+=to_string(n%2);
n/=2;
}
s+=to_string(n);
int count=0;
for (int i = 0; i <s.length(); ++i)
{
if(s[i]=='1') count++;
}
return count;
}
};