# 371. Sum-of-Two-Integers

difficulty: Medium

section pre{ background-color: #eee; border: 1px solid #ddd; padding:10px; border-radius: 5px; }

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

**Example 1:**

```
Input: a = 1, b = 2
Output: 3
```

**Example 2:**

```
Input: a = -2, b = 3
Output: 1
```

## Method One

参见 位操作的笔记部分。

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