mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-11-04 03:33:12 +08:00
35 lines
1.1 KiB
HTML
35 lines
1.1 KiB
HTML
<p>Given the <code>head</code> of a singly linked list, reverse the list, and return <em>the reversed list</em>.</p>
|
|
|
|
<p> </p>
|
|
<p><strong class="example">Example 1:</strong></p>
|
|
<img alt="" src="https://assets.leetcode.com/uploads/2021/02/19/rev1ex1.jpg" style="width: 542px; height: 222px;" />
|
|
<pre>
|
|
<strong>Input:</strong> head = [1,2,3,4,5]
|
|
<strong>Output:</strong> [5,4,3,2,1]
|
|
</pre>
|
|
|
|
<p><strong class="example">Example 2:</strong></p>
|
|
<img alt="" src="https://assets.leetcode.com/uploads/2021/02/19/rev1ex2.jpg" style="width: 182px; height: 222px;" />
|
|
<pre>
|
|
<strong>Input:</strong> head = [1,2]
|
|
<strong>Output:</strong> [2,1]
|
|
</pre>
|
|
|
|
<p><strong class="example">Example 3:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> head = []
|
|
<strong>Output:</strong> []
|
|
</pre>
|
|
|
|
<p> </p>
|
|
<p><strong>Constraints:</strong></p>
|
|
|
|
<ul>
|
|
<li>The number of nodes in the list is the range <code>[0, 5000]</code>.</li>
|
|
<li><code>-5000 <= Node.val <= 5000</code></li>
|
|
</ul>
|
|
|
|
<p> </p>
|
|
<p><strong>Follow up:</strong> A linked list can be reversed either iteratively or recursively. Could you implement both?</p>
|