leetcode-problemset/leetcode-cn/problem (Chinese)/参加考试的最大学生数 [maximum-students-taking-exam].html

<p>给你一个&nbsp;<code>m&nbsp;* n</code>&nbsp;的矩阵 <code>seats</code>&nbsp;表示教室中的座位分布。如果座位是坏的（不可用），就用&nbsp;<code>'#'</code>&nbsp;表示；否则，用&nbsp;<code>'.'</code>&nbsp;表示。</p>

<p>学生可以看到左侧、右侧、左上、右上这四个方向上紧邻他的学生的答卷，但是看不到直接坐在他前面或者后面的学生的答卷。请你计算并返回该考场可以容纳的同时参加考试且无法作弊的&nbsp;<strong>最大&nbsp;</strong>学生人数。</p>

<p>学生必须坐在状况良好的座位上。</p>

<p>&nbsp;</p>

<p><strong>示例 1：</strong></p>

<p><img src="https://assets.leetcode-cn.com/aliyun-lc-upload/uploads/2020/02/09/image.png" style="height: 197px; width: 339px;" /></p>

<pre>
<strong>输入：</strong>seats = [["#",".","#","#",".","#"],
&nbsp;             [".","#","#","#","#","."],
&nbsp;             ["#",".","#","#",".","#"]]
<strong>输出：</strong>4
<strong>解释：</strong>教师可以让 4 个学生坐在可用的座位上，这样他们就无法在考试中作弊。 
</pre>

<p><strong>示例 2：</strong></p>

<pre>
<strong>输入：</strong>seats = [[".","#"],
&nbsp;             ["#","#"],
&nbsp;             ["#","."],
&nbsp;             ["#","#"],
&nbsp;             [".","#"]]
<strong>输出：</strong>3
<strong>解释：</strong>让所有学生坐在可用的座位上。
</pre>

<p><strong>示例 3：</strong></p>

<pre>
<strong>输入：</strong>seats = [["#",".","<strong>.</strong>",".","#"],
&nbsp;             ["<strong>.</strong>","#","<strong>.</strong>","#","<strong>.</strong>"],
&nbsp;             ["<strong>.</strong>",".","#",".","<strong>.</strong>"],
&nbsp;             ["<strong>.</strong>","#","<strong>.</strong>","#","<strong>.</strong>"],
&nbsp;             ["#",".","<strong>.</strong>",".","#"]]
<strong>输出：</strong>10
<strong>解释：</strong>让学生坐在第 1、3 和 5 列的可用座位上。
</pre>

<p>&nbsp;</p>

<p><strong>提示：</strong></p>

<ul>
	<li><code>seats</code>&nbsp;只包含字符&nbsp;<code>'.'&nbsp;和</code><code>'#'</code></li>
	<li><code>m ==&nbsp;seats.length</code></li>
	<li><code>n ==&nbsp;seats[i].length</code></li>
	<li><code>1 &lt;= m &lt;= 8</code></li>
	<li><code>1 &lt;= n &lt;= 8</code></li>
</ul>