Deletion in Linked List

Deleting a node in a Linked List is an important operation and can be done in three main ways: removing the first node, removing a node in the middle, or removing the last node.

In this article, we will explore deletion operation on Linked List for all the above scenarios.

1. Deletion at the Beginning of Linked List

Deletion at the Beginning operation involves removing the first node of the linked list.

1. Check if the list is empty: If the head is NULL, the list is empty, and there's nothing to delete.
2. Update the head pointer: Set the head to the second node (head = head->next).
3. Delete the original head node: The original head node is now unreferenced, and it can be freed/deleted if necessary (in languages like C++ where memory management is manual).

To read more about Deletion at the Beginning Refer, Deletion at beginning (Removal of first node) in a Linked List

2. Deletion at Specific Position of Linked List

Deletion at a specified position in a linked list involves removing a node from a specific index/position, which can be the first, middle, or last node.

1. Check if the position is valid: If the position is out of bounds (greater than the length of the list), return an error or handle appropriately.
2. Traverse the list to find the node just before the one to be deleted: Start from the head and move through the list until reaching the node at position n-1 (one before the target position).
3. Update the next pointer: Set the next pointer of the (n-1)ᵗʰ node to point to the node after the target node (node_to_delete->next).
4. Delete the target node: The node to be deleted is now unreferenced, and in languages like C++ or Java, it can be safely deallocated.

To read more about Deletion at specific position Refer, Delete a Linked List node at a given position

3. Deletion at the End of Linked List

Deletion at the end operation involves removing the last node of the linked list.

1. Check if the list is empty: If the head is NULL, the list is empty, and there's nothing to delete.
2. If the list has only one node: Simply set the head to NULL (the list becomes empty).
3. Traverse the list to find the second-last node: Start from the head and iterate through the list until you reach the second-last node (where the next of the node is the last node).
4. Update the next pointer of the second-last node: Set the second-last node’s next to NULL (removing the link to the last node).
5. Delete the last node: The last node is now unreferenced and can be deleted or freed, depending on the language used.

To read more about Deletion at the end Refer, Deletion at end (Removal of last node) in a Linked List