LINK02P03 - Editorial

editorial
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Problem Link - Deletion in Circular Linked List

Problem Statement:

Study the function deleteNode in the IDE. After you have understood all the steps, delete the code and try to write it down yourself, to ensure that you have actually understood it. You can always check the solution if you are not able to figure something out.

Approach:

The key idea of this solution is to maintain a circular linked list where the last node’s next pointer connects back to the first node (head). This ensures that traversing the list can form a loop. The insertion of new elements is done efficiently using the tail pointer.

Here’s how the approach works:

  1. Node Structure:

    • A Node stores two things:
      • value: The data of the node.
      • next: A pointer that points to the next node in the list.

  2. insertAtEnd(int value):

    • A new node is created using the provided value.
    • If the list is empty (head == NULL), the new node becomes both the head and tail.
    • Otherwise, the new node is added after the current tail.
    • The tail is updated to this new node.
    • The new tail is then linked back to the head to maintain the circular structure.

Time Complexity:

  • insertAtEnd: O(1) since we directly update the tail pointer and make the circular connection without needing to traverse the list.

Space Complexity:

  • O(n) where n is the number of nodes, since we are storing n nodes in the linked list.