Why Do We Use Linked List in Data Structure?

A linked list is a fundamental data structure in computer science that allows us to store and manipulate a collection of elements. It consists of nodes where each node contains both data and a reference to the next node in the sequence. Unlike arrays, linked lists provide dynamic memory allocation, which means the size of a linked list can grow or shrink as needed.

Advantages of Linked List

Linked lists offer several advantages over other data structures:

Dynamic Size: One of the primary advantages of linked lists is their ability to efficiently handle elements with varying sizes. Unlike arrays, where memory needs to be allocated upfront, linked lists allow for dynamic memory allocation. This flexibility enables us to add or remove elements without worrying about resizing the data structure.
Efficient Insertion and Deletion: Insertion and deletion operations are often faster in linked lists compared to arrays. In an array, adding or removing an element requires shifting all subsequent elements to accommodate the change.
In a linked list, however, these operations only require updating a few references.
Memory Efficiency: Linked lists can be more memory-efficient than arrays when dealing with sparse data structures. Since each element only requires memory for its value and reference, a linked list can save memory by not allocating space for empty or null elements.
Flexibility: Linked lists provide flexibility in terms of reordering or rearranging elements. By simply changing the references between nodes, we can easily modify the order or structure of the list without affecting the entire data structure.

Types of Linked Lists

There are several types of linked lists, each with its own characteristics:

Singly Linked List

In a singly linked list, each node contains data and a reference to the next node. Traversing this type of list can only be done in one direction: from the head (the first node) to the tail (the last node). However, inserting or deleting nodes can be done efficiently by updating the appropriate references.

Doubly Linked List

A doubly linked list is similar to a singly linked list, but each node also has a reference to the previous node. This additional reference allows for easier traversal in both directions, making it convenient for operations that require backward navigation.

Circular Linked List

A circular linked list is a variation of singly or doubly linked lists where the last node’s reference points back to the first node (for singly circular) or both the first and last nodes (for doubly circular). This circular structure enables seamless traversal from any given point in the list.

Common Use Cases

Linked lists are widely used in various applications, including:

Implementation of Stacks and Queues: Linked lists provide a natural way to implement stacks and queues. In a stack, elements are added and removed from one end (top), while in a queue, elements are added at one end (rear) and removed from another end (front).
Dynamic Memory Allocation: Linked lists play a crucial role in dynamic memory allocation.
When we need memory at runtime, we can allocate it using linked lists rather than relying solely on static memory allocation.
Graphs and Trees: Many graph and tree data structures rely on linked lists to represent their nodes and connections. Linked lists are often used to maintain the children or neighbors of a particular node.
Operating Systems: Linked lists are widely used within operating systems for managing processes, files, and other data structures.

In conclusion, linked lists are an essential data structure in computer science due to their dynamic size, efficient insertion and deletion operations, memory efficiency, and flexibility. Understanding the advantages and types of linked lists can help you choose the appropriate data structure for your specific needs.