LeetCode-面试题65-不用加减乘除做加法

输入: a = 1, b = 1
输出: 2

class Solution {
    public int add(int a, int b) {
        int sum = 0;
        int carry = 0;
        do{
            sum = a^b; // 两数相加,且不考虑进位
            carry = (a&b)<<1; //得到进位
            a = sum;
            b = carry;
        }while(b!=0);
        return a;
    }
}