coder-xiaomo/leetcode-problemset
1
0
Fork 0
mirror of https://gitee.com/coder-xiaomo/leetcode-problemset synced 2025-09-05 23:41:41 +08:00
Code Issues Projects Releases Wiki Activity GitHub Gitee

update

Browse Source
This commit is contained in:
小墨
2022-03-29 12:55:24 +08:00
parent 2b0511d272
commit b84ae535b7
3973 changed files with 51044 additions and 105065 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
leetcode/problem/surrounded-regions.html Normal file
View File

@@ -0,0 +1,29 @@
<p>Given an <code>m x n</code> matrix <code>board</code> containing <code>&#39;X&#39;</code> and <code>&#39;O&#39;</code>, <em>capture all regions that are 4-directionally&nbsp;surrounded by</em> <code>&#39;X&#39;</code>.</p>
<p>A region is <strong>captured</strong> by flipping all <code>&#39;O&#39;</code>s into <code>&#39;X&#39;</code>s in that surrounded region.</p>
<p>&nbsp;</p>
<p><strong>Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/02/19/xogrid.jpg" style="width: 550px; height: 237px;" />
<pre>
<strong>Input:</strong> board = [[&quot;X&quot;,&quot;X&quot;,&quot;X&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;O&quot;,&quot;O&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;X&quot;,&quot;O&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;O&quot;,&quot;X&quot;,&quot;X&quot;]]
<strong>Output:</strong> [[&quot;X&quot;,&quot;X&quot;,&quot;X&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;X&quot;,&quot;X&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;X&quot;,&quot;X&quot;,&quot;X&quot;],[&quot;X&quot;,&quot;O&quot;,&quot;X&quot;,&quot;X&quot;]]
<strong>Explanation:</strong> Surrounded regions should not be on the border, which means that any &#39;O&#39; on the border of the board are not flipped to &#39;X&#39;. Any &#39;O&#39; that is not on the border and it is not connected to an &#39;O&#39; on the border will be flipped to &#39;X&#39;. Two cells are connected if they are adjacent cells connected horizontally or vertically.
</pre>
<p><strong>Example 2:</strong></p>
<pre>
<strong>Input:</strong> board = [[&quot;X&quot;]]
<strong>Output:</strong> [[&quot;X&quot;]]
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>
<ul>
<li><code>m == board.length</code></li>
<li><code>n == board[i].length</code></li>
<li><code>1 &lt;= m, n &lt;= 200</code></li>
<li><code>board[i][j]</code> is <code>&#39;X&#39;</code> or <code>&#39;O&#39;</code>.</li>
</ul>