A doubly linked list is a data structure that consists of a sequence of nodes, each of which contains a data element, and two links to other nodes in the sequence. The first link (the “forward” link) points to the next node in the sequence, and the second link (the “backward” link) points to the node that preceded the current node in the sequence.
1. Introduction to doubly list items
A doubly linked list is a type of linked list in which each node contains two links: one pointing to the next node in the list, and one pointing to the previous node. This allows for bidirectional traversal of the list. Additionally, because each node contains links to both the next and previous nodes, a doubly linked list does not require a separate pointer to the head of the list, as is the case with a singly linked list.
2. How to create a doubly list item
To create a doubly list item, you need to create two list items and put them together. The first list item will be the item that you want to put in the doubly list, and the second list item will be the one that you want to put in the list after the first item.
3. How to insert a doubly list item
To insert a doubly list item, first locate the position where you want to insert the item. Then create a new node with the data you want to insert. To do this, set the data field of the new node to the data you want to insert and set the next and previous fields to point to the nodes before and after the new node, respectively. Finally, adjust the previous and next fields of the nodes before and after the new node to point to the new node.
4. How to delete a doubly list item
Assuming you have a reference to the item you want to delete, you can remove it from a doubly linked list in three steps:
1. Unlink the item from its previous item.
2. Unlink the item from its next item.
3. Set the item’s previous and next pointers to null.
Doing all three of these steps is necessary to avoid any potential memory leaks. After unlinking the item from the list, you can safely delete it from memory.
5. How to update a doubly list item
If you want to update a doubly list item, you first need to find the item that you want to update. To do this, you can use the find() method. Once you have found the item, you can use the update() method to update the item.
6. Conclusion
As we have seen, a doubly linked list is a data structure that consists of a set of nodes, each of which contains two pointers. These pointers point to the previous and next nodes in the list, respectively. This allows for bidirectional traversal of the list.
Doubly linked lists have many advantages over singly linked lists, chief among them being the fact that they allow for bidirectional traversal. This means that you can move forwards and backwards through the list without having to keep track of two separate pointers. Additionally, doubly linked lists use less memory than singly linked lists, as they only require two pointers per node instead of three.
Overall, doubly linked lists are a powerful and efficient data structure that should be considered for any application that requires bidirectional traversal.
