Doubly linked lists

Now that we have a solid grounding on what a singly linked list is and the kind of operations that can be performed on it, we shall now turn our focus one notch higher to the topic of doubly linked lists.

A doubly linked list is somehow similar to a singly linked list in that we make use of the same fundamental idea of stringing nodes together. In a Singly linked list, there exists one link between each successive node. A node in a doubly linked list has two pointers: a pointer to the next node and a pointer to the previous node:

A node in a singly linked list can only determine the next node associated with it. But the referenced node or next node has no way of telling who is doing the referencing. The flow of direction is only one way.

In a doubly linked list, we add to each node the ability to not only reference the next node but also the previous node.

Let's examine the nature of the linkages that exist between two successive nodes for better understanding:

With the existence...