Doubly linked lists

A doubly linked list is quite similar to the singly linked list in the sense that we use the same fundamental concept of nodes along with how we can store data and links together, as we did in a singly linked list. The only difference between a singly linked list and a doubly linked list is that in a singly linked list, there is only one link between each successive node, whereas, in a doubly linked list, we have two pointers—a pointer to the next node and a pointer to the previous node. See the following Figure 4.18 of a node; there is a pointer to the next node and the previous node, which are set to None as there is no node attached to this node.

Figure 4.18: Represents a doubly linked list with a single node

A node in a singly linked list can only determine the next node associated with it. However, there is no link to go back from this referenced node. The direction of flow is only one way. In a doubly linked list, we solve this issue and...