Singly LinkedList vs Doubly LinkedList

A singly linked list is a data structure that consists of a sequence of elements, each of which contains a reference to the next element in the sequence. A doubly linked list, on the other hand, is similar to a singly linked list, but each element (referred to as a "node") contains references to both the next and the previous elements in the sequence.

Here are some key differences between singly linked lists and doubly linked lists:

Traversal: In a singly linked list, you can only traverse the list in one direction (from the head to the tail), as each node only contains a reference to the next node. In a doubly linked list, however, you can traverse the list in both directions (from the head to the tail and vice versa), as each node contains references to both the next and previous nodes.

Insertion and Deletion: In a singly linked list, inserting or deleting a node requires updating the next pointer of the previous node, which can be time-consuming. In a doubly linked list, on the other hand, inserting or deleting a node requires updating both the next and previous pointers of the adjacent nodes, which can be slightly more efficient.

Memory: In a singly linked list, each node only requires one reference, whereas in a doubly linked list, each node requires two references. Because of this, doubly linked lists typically use more memory than singly linked lists.

Reverse Traversal: In a singly linked list, you can only traverse the list in one direction, so it's not easy to traverse the list in reverse order. In a doubly linked list, you can easily traverse the list in reverse order, as each node contains a reference to the previous node, which makes it simple to traverse the list in reverse order.

In summary, singly linked lists are simpler and use less memory than doubly linked lists, but they can only be traversed in one direction and insertion/deletion operations are more difficult. Doubly linked lists are more versatile, as they can be traversed in both directions and insertion/deletion operations are more efficient, but they use more memory.