cousins-in-binary-tree.md

<p>In a binary tree, the root node is at depth <code>0</code>, and children of each depth <code>k</code> node are at depth <code>k+1</code>.</p>

<p>Two nodes of a binary tree are <em>cousins</em> if they have the same depth, but have <strong>different parents</strong>.</p>

<p>We are given the <code>root</code> of a binary tree with unique values, and the values <code>x</code>&nbsp;and <code>y</code>&nbsp;of two different nodes in the tree.</p>

<p>Return&nbsp;<code>true</code>&nbsp;if and only if the nodes corresponding to the values <code>x</code> and <code>y</code> are cousins.</p>

<p>&nbsp;</p>

<p><strong>Example 1:<br />
<img alt="" src="https://assets.leetcode.com/uploads/2019/02/12/q1248-01.png" style="width: 180px; height: 160px;" /></strong></p>

<pre>
<strong>Input: </strong>root = <span id="example-input-1-1">[1,2,3,4]</span>, x = <span id="example-input-1-2">4</span>, y = <span id="example-input-1-3">3</span>
<strong>Output: </strong><span id="example-output-1">false</span>
</pre>

<div>
<p><strong>Example 2:<br />
<img alt="" src="https://assets.leetcode.com/uploads/2019/02/12/q1248-02.png" style="width: 201px; height: 160px;" /></strong></p>

<pre>
<strong>Input: </strong>root = <span id="example-input-2-1">[1,2,3,null,4,null,5]</span>, x = <span id="example-input-2-2">5</span>, y = <span id="example-input-2-3">4</span>
<strong>Output: </strong><span id="example-output-2">true</span>
</pre>

<div>
<p><strong>Example 3:</strong></p>

<p><strong><img alt="" src="https://assets.leetcode.com/uploads/2019/02/13/q1248-03.png" style="width: 156px; height: 160px;" /></strong></p>

<pre>
<strong>Input: </strong>root = <span id="example-input-3-1">[1,2,3,null,4]</span>, x = 2, y = 3
<strong>Output: </strong><span id="example-output-3">false</span></pre>

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

<ol>
	<li>The number of nodes in the tree will be between <code>2</code> and <code>100</code>.</li>
	<li>Each node has a unique integer value from <code>1</code> to <code>100</code>.</li>
</ol>

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<div>&nbsp;</div>
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