Fetch the repository succeeded.
This action will force synchronization from 小墨/力扣题库（完整版）, which will overwrite any changes that you have made since you forked the repository, and can not be recovered!!!
Synchronous operation will process in the background and will refresh the page when finishing processing. Please be patient.
<p>Due to a bug, there are many duplicate folders in a file system. You are given a 2D array <code>paths</code>, where <code>paths[i]</code> is an array representing an absolute path to the <code>i<sup>th</sup></code> folder in the file system.</p>
<ul>
<li>For example, <code>["one", "two", "three"]</code> represents the path <code>"/one/two/three"</code>.</li>
</ul>
<p>Two folders (not necessarily on the same level) are <strong>identical</strong> if they contain the <strong>same non-empty</strong> set of identical subfolders and underlying subfolder structure. The folders <strong>do not</strong> need to be at the root level to be identical. If two or more folders are <strong>identical</strong>, then <strong>mark</strong> the folders as well as all their subfolders.</p>
<ul>
<li>For example, folders <code>"/a"</code> and <code>"/b"</code> in the file structure below are identical. They (as well as their subfolders) should <strong>all</strong> be marked:
<ul>
<li><code>/a</code></li>
<li><code>/a/x</code></li>
<li><code>/a/x/y</code></li>
<li><code>/a/z</code></li>
<li><code>/b</code></li>
<li><code>/b/x</code></li>
<li><code>/b/x/y</code></li>
<li><code>/b/z</code></li>
</ul>
</li>
<li>However, if the file structure also included the path <code>"/b/w"</code>, then the folders <code>"/a"</code> and <code>"/b"</code> would not be identical. Note that <code>"/a/x"</code> and <code>"/b/x"</code> would still be considered identical even with the added folder.</li>
</ul>
<p>Once all the identical folders and their subfolders have been marked, the file system will <strong>delete</strong> all of them. The file system only runs the deletion once, so any folders that become identical after the initial deletion are not deleted.</p>
<p>Return <em>the 2D array </em><code>ans</code> <em>containing the paths of the <strong>remaining</strong> folders after deleting all the marked folders. The paths may be returned in <strong>any</strong> order</em>.</p>
<p> </p>
<p><strong>Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/07/19/lc-dupfolder1.jpg" style="width: 200px; height: 218px;" />
<pre>
<strong>Input:</strong> paths = [["a"],["c"],["d"],["a","b"],["c","b"],["d","a"]]
<strong>Output:</strong> [["d"],["d","a"]]
<strong>Explanation:</strong> The file structure is as shown.
Folders "/a" and "/c" (and their subfolders) are marked for deletion because they both contain an empty
folder named "b".
</pre>
<p><strong>Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/07/19/lc-dupfolder2.jpg" style="width: 200px; height: 355px;" />
<pre>
<strong>Input:</strong> paths = [["a"],["c"],["a","b"],["c","b"],["a","b","x"],["a","b","x","y"],["w"],["w","y"]]
<strong>Output:</strong> [["c"],["c","b"],["a"],["a","b"]]
<strong>Explanation: </strong>The file structure is as shown.
Folders "/a/b/x" and "/w" (and their subfolders) are marked for deletion because they both contain an empty folder named "y".
Note that folders "/a" and "/c" are identical after the deletion, but they are not deleted because they were not marked beforehand.
</pre>
<p><strong>Example 3:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/07/19/lc-dupfolder3.jpg" style="width: 200px; height: 201px;" />
<pre>
<strong>Input:</strong> paths = [["a","b"],["c","d"],["c"],["a"]]
<strong>Output:</strong> [["c"],["c","d"],["a"],["a","b"]]
<strong>Explanation:</strong> All folders are unique in the file system.
Note that the returned array can be in a different order as the order does not matter.
</pre>
<p> </p>
<p><strong>Constraints:</strong></p>
<ul>
<li><code>1 <= paths.length <= 2 * 10<sup>4</sup></code></li>
<li><code>1 <= paths[i].length <= 500</code></li>
<li><code>1 <= paths[i][j].length <= 10</code></li>
<li><code>1 <= sum(paths[i][j].length) <= 2 * 10<sup>5</sup></code></li>
<li><code>path[i][j]</code> consists of lowercase English letters.</li>
<li>No two paths lead to the same folder.</li>
<li>For any folder not at the root level, its parent folder will also be in the input.</li>
</ul>
此处可能存在不合适展示的内容，页面不予展示。您可通过相关编辑功能自查并修改。
如您确认内容无涉及 不当用语 / 纯广告导流 / 暴力 / 低俗色情 / 侵权 / 盗版 / 虚假 / 无价值内容或违法国家有关法律法规的内容，可点击提交进行申诉，我们将尽快为您处理。
马建仓 AI 助手