Sort a "K" Sorted Doubly Linked List

Given a doubly-linked list with N nodes, where each node’s position deviates at most K positions from its position in the sorted list, your task is to sort this given doubly linked list.

Example:

Let us consider K is 3. An element at position 4 in the sorted doubly linked list can be at positions 1, 2, 3, 4, 5, 6, 7 in the given linked list because the absolute difference of all these indices with 4 is at most 3.

Input:

The input starts with an integer 'T', representing the number of test cases.
For each test case:
 - A line containing integer 'K'.
 - A second line with the elements of the doubly linked list separated by spaces and terminated by -1. -1 is not part of the list.

Output:

For each test case, output the sorted elements of the linked list in a single line, separated by spaces, and terminated by -1.

Constraints:

• 1 <= T <= 10
• 1 <= N <= 10000
• 1 <= K < N

Note:

All elements in the doubly linked list are distinct. A doubly linked list can be traversed in both directions, forward and backward. Implement the function as required. Printing is handled separately.