leetcode-problemset/leetcode-cn/problem (English)/二叉树的右视图(English) [binary-tree-right-side-view].html

<p>Given the <code>root</code> of a binary tree, imagine yourself standing on the <strong>right side</strong> of it, return <em>the values of the nodes you can see ordered from top to bottom</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">root = [1,2,3,null,5,null,4]</span></p>

<p><strong>Output:</strong> <span class="example-io">[1,3,4]</span></p>

<p><strong>Explanation:</strong></p>

<p><img alt="" src="https://assets.leetcode.com/uploads/2024/11/24/tmpd5jn43fs-1.png" style="width: 400px; height: 207px;" /></p>
</div>

<p><strong class="example">Example 2:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">root = [1,2,3,4,null,null,null,5]</span></p>

<p><strong>Output:</strong> <span class="example-io">[1,3,4,5]</span></p>

<p><strong>Explanation:</strong></p>

<p><img alt="" src="https://assets.leetcode.com/uploads/2024/11/24/tmpkpe40xeh-1.png" style="width: 400px; height: 214px;" /></p>
</div>

<p><strong class="example">Example 3:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">root = [1,null,3]</span></p>

<p><strong>Output:</strong> <span class="example-io">[1,3]</span></p>
</div>

<p><strong class="example">Example 4:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">root = []</span></p>

<p><strong>Output:</strong> <span class="example-io">[]</span></p>
</div>

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

<ul>
	<li>The number of nodes in the tree is in the range <code>[0, 100]</code>.</li>
	<li><code>-100 &lt;= Node.val &lt;= 100</code></li>
</ul>