leetcode-problemset/leetcode-cn/problem (English)/回文链表(English) [palindrome-linked-list-lcci].html

<p>Implement a function to check if a linked list is a palindrome.</p>

<p>&nbsp;</p>

<p><strong>Example 1: </strong></p>

<pre>
<strong>Input:  </strong>1-&gt;2
<strong>Output: </strong> false 
</pre>

<p><strong>Example 2: </strong></p>

<pre>
<strong>Input:  </strong>1-&gt;2-&gt;2-&gt;1
<strong>Output: </strong> true 
</pre>

<p>&nbsp;</p>

<p><b>Follow up:</b><br />
Could you do it in O(n) time and O(1) space?</p>