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.

public class Solution {
    // you need to treat n as an unsigned value
    public int hammingWeight(int n) {
        int times  = 32; 
        int ones = 0;
        while (times > 0) {
            //check if the lowest digit is 1 
            if ((n & 1) == 1) {
                ones ++; 
            } 
            //right shift 1, so that we could check the next lower digit.
            n = n >> 1; 
            times--;
        }
        return ones; 
    }
}

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