README.md

comments	difficulty	edit_url
true	简单	https://github.com/doocs/leetcode/edit/main/lcci/17.01.Add%20Without%20Plus/README.md

面试题 17.01. 不用加号的加法

English Version

题目描述

设计一个函数把两个数字相加。不得使用 + 或者其他算术运算符。

示例:

输入: a = 1, b = 1
输出: 2

 

提示：

• a, b 均可能是负数或 0
• 结果不会溢出 32 位整数

解法

方法一

Java

class Solution {
    public int add(int a, int b) {
        int sum = 0, carry = 0;
        while (b != 0) {
            sum = a ^ b;
            carry = (a & b) << 1;
            a = sum;
            b = carry;
        }
        return a;
    }
}

Swift

class Solution {
    func add(_ a: Int, _ b: Int) -> Int {
        var a = a
        var b = b
        var sum = 0
        var carry = 0

        while b != 0 {
            sum = a ^ b
            carry = (a & b) << 1
            a = sum
            b = carry
        }

        return a
    }
}