# Problem Definition

## Description

Given a singly linked list, determine if it is a palindrome.

**Example 1:**

```plaintext
Input: 1->2
Output: false
```

**Example 2:**

```plaintext
Input: 1->2->2->1
Output: true
```

**Follow up:**

Could you do it in O(n) time and O(1) space?

## Notes

1. [LeetCode discussion - Java, easy to understand](https://leetcode.com/explore/interview/card/top-interview-questions-easy/93/linked-list/772/discuss/64501/Java-easy-to-understand)