leetcode-problemset/leetcode-cn/problem (English)/找出克隆二叉树中的相同节点(English) [find-a-corresponding-node-of-a-binary-tree-in-a-clone-of-that-tree].html

<p>Given two binary trees <code>original</code> and <code>cloned</code> and given a reference to a node <code>target</code> in the original tree.</p>

<p>The <code>cloned</code> tree is a <strong>copy of</strong> the <code>original</code> tree.</p>

<p>Return <em>a reference to the same node</em> in the <code>cloned</code> tree.</p>

<p><strong>Note</strong> that you are <strong>not allowed</strong> to change any of the two trees or the <code>target</code> node and the answer <strong>must be</strong> a reference to a node in the <code>cloned</code> tree.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/02/21/e1.png" style="width: 544px; height: 426px;" />
<pre>
<strong>Input:</strong> tree = [7,4,3,null,null,6,19], target = 3
<strong>Output:</strong> 3
<strong>Explanation:</strong> In all examples the original and cloned trees are shown. The target node is a green node from the original tree. The answer is the yellow node from the cloned tree.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/02/21/e2.png" style="width: 221px; height: 159px;" />
<pre>
<strong>Input:</strong> tree = [7], target =  7
<strong>Output:</strong> 7
</pre>

<p><strong class="example">Example 3:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/02/21/e3.png" style="width: 459px; height: 486px;" />
<pre>
<strong>Input:</strong> tree = [8,null,6,null,5,null,4,null,3,null,2,null,1], target = 4
<strong>Output:</strong> 4
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li>The number of nodes in the <code>tree</code> is in the range <code>[1, 10<sup>4</sup>]</code>.</li>
	<li>The values of the nodes of the <code>tree</code> are unique.</li>
	<li><code>target</code> node is a node from the <code>original</code> tree and is not <code>null</code>.</li>
</ul>

<p>&nbsp;</p>
<p><strong>Follow up:</strong> Could you solve the problem if repeated values on the tree are allowed?</p>