Given a doubly linked list, write a function to sort the doubly linked list in increasing order using merge sort.
For example, the following doubly linked list should be changed to 24810
Merge sort for singly linked list is already discussed. The important change here is to modify the previous pointers also when merging two lists.
Below is the implementation of merge sort for doubly linked list.
Linked List after sorting Forward Traversal using next pointer 3 4 5 10 20 30 Backward Traversal using prev pointer 30 20 10 5 4 3
Thanks to Goku for providing above implementation in a comment here.
Time Complexity: Time complexity of the above implementation is same as time complexity of MergeSort for arrays. It takes Θ(nLogn) time.
You may also like to see QuickSort for doubly linked list
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above