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.


 1 public class Solution 
 2 {
 3     // you need to treat n as an unsigned value
 4     public static int hammingWeight(int n)
 5     {
 6         
 7         int cout=0;
 8         for(int i=0;i<32;i++,n=n>>1)
 9             if((n&1)==1)
10                 cout++;
11         return cout;
12     }
13     public static void main(String args[])
14     {
15         int n=15;
16         System.out.println(hammingWeight(n));
17     }
18 }