Given singly linked list with every node having an additional “arbitrary” pointer that currently points to NULL. Need to make the “arbitrary” pointer point to the next higher value node.
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A Simple Solution is to traverse all nodes one by one, for every node, find the node which has next greater value of the current node and changes the next pointer. Time Complexity of this solution is O(n2).
An Efficient Solution works in O(nLogn) time. The idea is to use Merge Sort for linked list.
1) Traverse input list and copy next pointer to arbit pointer for every node.
2) Do Merge Sort for the linked list formed by arbit pointers.
Below is the implementation of the above idea. All of the merger sort functions are taken from here. The taken functions are modified here so that they work on arbit pointers instead of next pointers.
Result Linked List is: Traversal using Next Pointer 5, 10, 2, 3, Traversal using Arbit Pointer 2, 3, 5, 10,
This article is contributed by Saurabh Bansal. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above
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