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: 1234NULL, X: 9

Output:

1

Explanation:

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

Constraints:

1

Question

Triplets in a Sorted Doubly Linked List

Given a sorted doubly linked list of distinct nodes, find and count triplets with a sum equal to a given value 'X'.

Iterate through the list and for each node, use two pointers to find the other two no...read more

Example:

Input:

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

Output:

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.

Accepted Answer

Given a sorted doubly linked list of distinct nodes, find and count triplets with a sum equal to a given value 'X'.

Iterate through the list and for each node, use two pointers to find the other two nodes that sum up to 'X'.
Keep track of the count of triplets found and return it at the end.
Handle edge cases like when the list has less than 3 nodes or no triplets are found.