# 反转字符串
<p>编写一个函数，其作用是将输入的字符串反转过来。输入字符串以字符数组 <code>s</code> 的形式给出。</p>

<p>不要给另外的数组分配额外的空间，你必须<strong><a href="https://baike.baidu.com/item/原地算法" target="_blank">原地</a>修改输入数组</strong>、使用 O(1) 的额外空间解决这一问题。</p>

<p>&nbsp;</p>

<p><strong>示例 1：</strong></p>

<pre>
<strong>输入：</strong>s = ["h","e","l","l","o"]
<strong>输出：</strong>["o","l","l","e","h"]
</pre>

<p><strong>示例 2：</strong></p>

<pre>
<strong>输入：</strong>s = ["H","a","n","n","a","h"]
<strong>输出：</strong>["h","a","n","n","a","H"]</pre>

<p>&nbsp;</p>

<p><strong>提示：</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 10<sup>5</sup></code></li>
	<li><code>s[i]</code> 都是 <a href="https://baike.baidu.com/item/ASCII" target="_blank">ASCII</a> 码表中的可打印字符</li>
</ul>

<p>以下错误的选项是？</p>
## aop
### before
```cpp

```
### after
```cpp

```

## 答案
```cpp

```
## 选项

### A
```cpp

```

### B
```cpp

```

### C
```cpp

```
