mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-01-11 19:18:14 +08:00
34 lines
931 B
HTML
34 lines
931 B
HTML
|
<p>给你二叉树的根节点 <code>root</code> ，返回其节点值的 <strong>锯齿形层序遍历</strong> 。（即先从左往右，再从右往左进行下一层遍历，以此类推，层与层之间交替进行）。</p>
|
|||
|
|
|
|||
|
|
<p> </p>
|
|||
|
|
|
|||
|
|
<p><strong>示例 1：</strong></p>
|
|||
|
|
<img alt="" src="https://assets.leetcode.com/uploads/2021/02/19/tree1.jpg" style="width: 277px; height: 302px;" />
|
|||
|
|
<pre>
|
|||
|
|
<strong>输入：</strong>root = [3,9,20,null,null,15,7]
|
|||
|
|
<strong>输出：</strong>[[3],[20,9],[15,7]]
|
|||
|
|
</pre>
|
|||
|
|
|
|||
|
|
<p><strong>示例 2：</strong></p>
|
|||
|
|
|
|||
|
|
<pre>
|
|||
|
|
<strong>输入：</strong>root = [1]
|
|||
|
|
<strong>输出：</strong>[[1]]
|
|||
|
|
</pre>
|
|||
|
|
|
|||
|
|
<p><strong>示例 3：</strong></p>
|
|||
|
|
|
|||
|
|
<pre>
|
|||
|
|
<strong>输入：</strong>root = []
|
|||
|
|
<strong>输出：</strong>[]
|
|||
|
|
</pre>
|
|||
|
|
|
|||
|
|
<p> </p>
|
|||
|
|
|
|||
|
|
<p><strong>提示：</strong></p>
|
|||
|
|
|
|||
|
|
<ul>
|
|||
|
|
<li>树中节点数目在范围 <code>[0, 2000]</code> 内</li>
|
|||
|
|
<li><code>-100 <= Node.val <= 100</code></li>
|
|||
|
|
</ul>
|