Difference between Singly and Doubly Linked List:
When it comes to implementing data structures in computer science, linked lists are one of the most fundamental data structures. It is a collection of data elements, where each element points to the next element. There are two types of linked lists, Singly and Doubly linked lists. In this article, we will explore the difference between the two.
Singly Linked List:
In a singly linked list, each element of the list contains two fields: one that stores the actual data and another that stores the address of the next element in the list. The last element of the list points to null. This means that singly linked lists can only be traversed in one direction, i.e., from the first element to the last element.
Singly linked lists are used in various applications, such as stack and queue implementation, as well as image processing, digitized speech recognition, and computational biology. It requires less memory, which makes it useful in situations where memory utilization is a concern.
Doubly Linked List:
A doubly linked list is similar to a singly linked list, except that each element in the list contains an additional field that points to the previous element in the list. This means that a doubly linked list can be traversed in both directions – from the first element to the last element and vice versa.
Doubly linked lists are used in various applications, such as music players, where songs can be played in both forward and reverse order. It requires more memory than singly linked lists, but it is worth the additional memory to provide the ability to traverse the list in both directions.
Conclusion:
In summary, the main difference between singly and doubly linked lists is the number of pointers each element contains. Singly linked lists have one pointer – to the next element, whereas doubly linked lists have two pointers – one to the next element and one to the previous element. Singly linked lists are used in situations where memory utilization is a concern. Doubly linked lists are used in situations where the ability to traverse the list in both directions is required. It’s essential to choose the appropriate type of linked list while implementing a particular application.
Table difference between singly and doubly linked list
| Feature | Singly Linked List | Doubly Linked List |
|---|---|---|
| Structure | Each node only contains a reference to the next node. | Each node contains references to both the next and previous nodes. |
| Traversal | Traversal can only be done in one direction (from head to tail). | Traversal can be done in both directions (from head to tail and from tail to head). |
| Insertion | Insertion can only be done at the head or the tail of the list. | Insertion can be done at any position in the list. |
| Deletion | Deletion of a node requires the previous node’s reference to be updated. | Deletion of a node requires both the previous and next nodes’ references to be updated. |
| Memory usage | Uses less memory as each node only contains one reference. | Uses more memory as each node contains two references. |