191. Number of 1 Bits#1(Done)

Solution#1(2ms)

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;
    }
}

Solution#2

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

Problem
1. >>>無符號位右移(補零)，>>右移