Embedded Prep

Introduction to Linked List

If you’re learning Linked List data structures, you’ve probably come across the term Linked List. But what exactly is it? How does it work, and why do we even need it when we already have arrays?

In this blog post, we’ll dive deep into linked list in data structure, understand how it differs from other data structures, explore the types of linked list, and learn about their practical advantages and use cases.

What is a Linked List?

A Linked List is a linear data structure where elements are stored in nodes, and each node points to the next one in the sequence. Unlike arrays, which store elements in contiguous memory locations, linked lists store data non-contiguously and use pointers to connect elements.

Each node in a linked list contains:

• Data (the value stored in the node)
• Pointer (or reference) to the next node

This unique structure makes linked lists highly flexible and efficient in certain scenarios.

Why Use Linked List Instead of Arrays?

Before diving into the types of linked list, let’s quickly understand why we’d choose a linked list over an array:

✅ Dynamic Size: Unlike arrays, linked lists don’t require specifying size in advance. Nodes can be added or removed without reallocating memory.

✅ Efficient Insertions/Deletions: Adding or removing elements doesn’t involve shifting elements, as in arrays.

✅ Memory Utilization: Useful when memory is fragmented or when the size of the dataset changes frequently.

However, linked lists also have some disadvantages, like higher memory usage due to storing pointers and slower random access.

Types of Linked List

There are several types of linked list, each serving different use cases:

1. Singly Linked List

• Each node has a reference to the next node only.
• Traversal is possible only in one direction.
• Simple and widely used in basic implementations.

Example:

[10] → [20] → [30] → NULL

2. Doubly Linked List

• Each node has references to both next and previous nodes.
• Allows traversal in both directions (forward and backward).
• Slightly higher memory usage due to the extra pointer.

Example:

NULL ← [10] ↔ [20] ↔ [30] → NULL

3. Circular Linked List

• Last node points back to the first node, creating a circle.
• Can be singly or doubly linked.
• Useful in applications like round-robin scheduling.

Example:

[10] → [20] → [30] → [10] …

Common Linked List Operations

Understanding basic linked list operations is crucial. Let’s look at the most common:

Insertion

• Insert a new node at the beginning, middle, or end of the list.

Deletion

• Remove a node based on value or position.

Traversal

• Visit each node and perform an action (like printing values).

Searching

• Find whether a particular value exists in the linked list.

Advantages of Linked List

Let’s recap some advantages of linked list:

• Dynamic memory allocation
• No wasted memory (no predefined size)
• Easier insertion/deletion
• Useful for implementing stacks, queues, graphs, and more

Applications of Linked List

Here are some practical uses of linked list in data structure:

• Implementing stacks and queues
• Dynamic memory management
• Browser history (back and forward functionality)
• Undo/redo features in software
• Hash table chaining

Linked List vs Array: Quick Comparison

Feature	Array	Linked List
Size	Fixed	Dynamic
Memory Allocation	Contiguous	Non-contiguous
Insertion/Deletion	Costly (shifting)	Efficient
Random Access	O(1)	O(n)

Conclusion

A Linked List is a powerful and flexible data structure essential for any programmer’s toolkit. While it might seem complex initially, it offers significant advantages, especially when dealing with dynamic data and frequent insertions or deletions.

Whether you’re preparing for coding interviews or simply expanding your programming knowledge, mastering linked list in data structure will give you a strong foundation for solving complex problems efficiently.

Frequently Asked Questions (FAQ)

Q1. What is a linked list in simple words?
A linked list is a sequence of nodes where each node points to the next, making it easy to add or remove elements without shifting other data.

Q2. Is linked list better than array?
It depends. Linked lists are better for frequent insertions/deletions, but arrays are better for fast random access.

Q3. What are the types of linked list?
The main types include singly linked list, doubly linked list, and circular linked list.

Q4. Where is linked list used in real life?
Linked lists are used in browser history, memory management, music playlists, and many other applications.