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            "title": "N-ary Tree Postorder Traversal",
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            "content": "<p>Given the <code>root</code> of an n-ary tree, return <em>the postorder traversal of its nodes&#39; values</em>.</p>\n\n<p>Nary-Tree input serialization is represented in their level order traversal. Each group of children is separated by the null value (See examples)</p>\n\n<p>&nbsp;</p>\n<p><strong>Example 1:</strong></p>\n<img src=\"https://assets.leetcode.com/uploads/2018/10/12/narytreeexample.png\" style=\"width: 100%; max-width: 300px;\" />\n<pre>\n<strong>Input:</strong> root = [1,null,3,2,4,null,5,6]\n<strong>Output:</strong> [5,6,3,2,4,1]\n</pre>\n\n<p><strong>Example 2:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2019/11/08/sample_4_964.png\" style=\"width: 296px; height: 241px;\" />\n<pre>\n<strong>Input:</strong> root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14]\n<strong>Output:</strong> [2,6,14,11,7,3,12,8,4,13,9,10,5,1]\n</pre>\n\n<p>&nbsp;</p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li>The number of nodes in the tree is in the range <code>[0, 10<sup>4</sup>]</code>.</li>\n\t<li><code>0 &lt;= Node.val &lt;= 10<sup>4</sup></code></li>\n\t<li>The height of the n-ary tree is less than or equal to <code>1000</code>.</li>\n</ul>\n\n<p>&nbsp;</p>\n<p><strong>Follow up:</strong> Recursive solution is trivial, could you do it iteratively?</p>\n",
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