191. 位1的个数

主要记住怎么遍历取出n的最右边的数字

public class Solution {
    // you need to treat n as an unsigned value
    public int hammingWeight(int n) {
        int ans = 0;
        for (int i = 0; i < 32 && n != 0; ++i) {
            if ((n & 1) == 1) ++ans;
            n >>>= 1;
        }
        return ans;
    }
}