# 最大正方形
<p>在一个由 <code>'0'</code> 和 <code>'1'</code> 组成的二维矩阵内，找到只包含 <code>'1'</code> 的最大正方形，并返回其面积。</p>

<p> </p>

<p><strong>示例 1：</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/11/26/max1grid.jpg" style="width: 400px; height: 319px;" />
<pre>
<strong>输入：</strong>matrix = [["1","0","1","0","0"],["1","0","1","1","1"],["1","1","1","1","1"],["1","0","0","1","0"]]
<strong>输出：</strong>4
</pre>

<p><strong>示例 2：</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/11/26/max2grid.jpg" style="width: 165px; height: 165px;" />
<pre>
<strong>输入：</strong>matrix = [["0","1"],["1","0"]]
<strong>输出：</strong>1
</pre>

<p><strong>示例 3：</strong></p>

<pre>
<strong>输入：</strong>matrix = [["0"]]
<strong>输出：</strong>0
</pre>

<p> </p>

<p><strong>提示：</strong></p>

<ul>
	<li><code>m == matrix.length</code></li>
	<li><code>n == matrix[i].length</code></li>
	<li><code>1 <= m, n <= 300</code></li>
	<li><code>matrix[i][j]</code> 为 <code>'0'</code> 或 <code>'1'</code></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

```
