Triplets in a Sorted Doubly Linked List

Given a sorted doubly linked list of distinct nodes, determine how many triplets in the list have a sum equal to a given value 'X'. Each node in the list contains a unique integer. Your goal is to find and count such triplets.

Example:

Input:

DLL: 1<->2<->3<->4<->NULL, X: 9

Output:

1

Explanation:

The only triplet with the sum of 9 is (2, 3, 4).

Constraints:

• 1 <= 'T' <= 10
• 3 <= 'N' <= 100
• 1 <= 'X' <= 10⁸
• 1 <= 'V' <= 10⁸
• The linked list has distinct nodes.

Input:

The first line of input contains an integer 'T' representing the number of test cases.

For each test case:
The first line contains space-separated integers representing the nodes of the linked list, ending with -1.
The second line contains a single integer 'X' indicating the triplet sum value.

Output:

Output an integer for each test case, representing the count of triplets, printed on a new line.

Note:

If no triplets are found, return 0. You are not required to print anything; just implement the function to return the result.