Number of 1 Bits

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

看了reverse bites就很容易理解这道题了