题目：给你一个int型的整数，返回它二进制中1的个数，注意可能给负数
思路：用无符号右移可以解决负数的情况，while循环的条件要变成不等于0
public class Solution { // you need to treat n as an unsigned value public int hammingWeight(int n) { int count = 0; while (n != 0) { count += n & 1; n >>>= 1; } return count; } }