> For the complete documentation index, see [llms.txt](https://imhuay.gitbook.io/studies/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://imhuay.gitbook.io/studies/algorithms/problems/2022/01/jian-zhi-offer6500-jian-dan-bu-yong-jia-jian-cheng-chu-zuo-jia-fa.md).

# 不用加减乘除做加法

![last modify](https://img.shields.io/static/v1?label=last%20modify\&message=2022-10-14%2014%3A59%3A33\&color=yellowgreen\&style=flat-square) [![](https://img.shields.io/static/v1?label=\&message=%E7%AE%80%E5%8D%95\&color=yellow\&style=flat-square)](https://imhuay.gitbook.io/studies/algorithms/problems/2022/01/pages/R5NyOzkn3qAZy7wCx1pS#简单) [![](https://img.shields.io/static/v1?label=\&message=%E5%89%91%E6%8C%87Offer\&color=green\&style=flat-square)](https://imhuay.gitbook.io/studies/algorithms/problems/2022/01/pages/R5NyOzkn3qAZy7wCx1pS#剑指offer) [![](https://img.shields.io/static/v1?label=\&message=%E4%BD%8D%E8%BF%90%E7%AE%97\&color=blue\&style=flat-square)](https://imhuay.gitbook.io/studies/algorithms/problems/2022/01/pages/R5NyOzkn3qAZy7wCx1pS#位运算)

**问题简述**

```
求两个整数之和，要求不能使用 “+”、“-”、“*”、“/” 运算符号。
```

<details>

<summary><strong>详细描述</strong></summary>

```
写一个函数，求两个整数之和，要求在函数体内不得使用 “+”、“-”、“*”、“/” 四则运算符号。

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

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/bu-yong-jia-jian-cheng-chu-zuo-jia-fa-lcof
著作权归领扣网络所有。商业转载请联系官方授权，非商业转载请注明出处。
```

</details>

**思路**

![](/files/kat5PWWKjdV8sxswJTV1)

> [不用加减乘除做加法（位运算，清晰图解）](https://leetcode-cn.com/problems/bu-yong-jia-jian-cheng-chu-zuo-jia-fa-lcof/solution/mian-shi-ti-65-bu-yong-jia-jian-cheng-chu-zuo-ji-7/)

* 不用编程语言之间略有区别；

<details>

<summary><strong>Java（推荐）</strong></summary>

```java
class Solution {
    public int add(int a, int b) {
        while(b != 0) { // 当进位为 0 时跳出
            int c = (a & b) << 1;  // c = 进位
            a ^= b; // a = 非进位和
            b = c; // b = 进位
        }
        return a;
    }
}
```

</details>

<details>

<summary><strong>Python</strong></summary>

* Python 中

```python
class Solution:
    def add(self, a: int, b: int) -> int:
        x = 0xffffffff
        a, b = a & x, b & x  # 转为补码形式
        while b != 0:
            a, b = (a ^ b), (a & b) << 1 & x
        return a if a <= 0x7fffffff else ~(a ^ x)  # 还原
```

</details>

<details>

<summary><strong>C++</strong></summary>

[不用加减乘除做加法](https://leetcode-cn.com/problems/bu-yong-jia-jian-cheng-chu-zuo-jia-fa-lcof/solution/dian-zan-yao-wo-zhi-dao-ni-xiang-kan-dia-ovxy/)

```cpp
class Solution {
public:
    int add(int a, int b) {
        while (b) {
            int carry = a & b; // 计算 进位
            a = a ^ b; // 计算 本位
            b = (unsigned)carry << 1;  // C++中负数不支持左位移
        }
        return a;
    }
};
```

</details>