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.

Subscribe to see which companies asked this question

public class Solution {
// you need to treat n as an unsigned value
public int hammingWeight(int n) {
int count = 0;
while(n!=0){
n = n&(n - 1);
++count;
}
return count;
}
}