191. 位1的个数

public class Solution {
    // you need to treat n as an unsigned value
    public int hammingWeight(int n) {
        int weight = 0;
        while (n != 0) {
            if ((n & 1) == 1) {//负数求余数可能得-1，所以得写成 if((n%2)==1||(n%2)==-1)
                weight++;
            }
            n = n >>> 1;//注意>>> >>的区别
        }
        return weight;
    }
}