371. Sum of Two Integers java solutions

Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -.

Example:
Given a = 1 and b = 2, return 3.

Credits:
Special thanks to @fujiaozhu for adding this problem and creating all test cases.

public class Solution {
    public int getSum(int a, int b) {
        int sum = a^b;//保留二进制和中两位不相同的位
        int carry = a&b;//保留二进制中两个都为1 的位置
        int tmp = 0;
        while(carry != 0){
            carry = carry << 1;// 通过移位来循环计算，将值加上
            tmp = sum;
            sum ^= carry;
            carry &= tmp;
        }
        return sum;
    }
}

这是leetcode 比较新的一题，挺有意思的。