Palindromic Linked List Problem Statement

Given a singly linked list of integers, determine if it is a palindrome. Return true if it is a palindrome, otherwise return false.

Example:

Input:

1 -> 2 -> 3 -> 2 -> 1 -> NULL

Output:

true

Explanation:

The linked list is the same forwards and backwards, hence it is a palindrome.

Constraints:

• 1 <= T <= 10
• 0 <= L <= 10⁵
• 1 <= data <= 10⁹ and data ≠ -1
• The problem should ideally be solved in O(N) time complexity and O(1) space complexity.

Input:

The first line contains an integer 'T' indicating the number of test cases. For each test case, the line contains the linked list elements separated by spaces, ending with -1 which is not a list element.

Output:

For each test case, output “true” or “false” on a new line corresponding to whether the linked list is a palindrome.

Note:

You do not need to handle any input/output tasks, focus on implementing the function logic.