The Data Structure That Powers Stacks & Queues

Imagine a treasure hunt…

Each clue tells you where the next clue is.

That’s exactly how a Linked List works.

Instead of storing elements side-by-side like arrays,
each node stores:

• data
• a reference to the next node

1. What is a Linked List?

A Linked List is a linear data structure made of nodes.

Each node contains:

• actual data
• link to next node

Node Structure in Java

public class Node {

int data;
Node next;

public Node(int data) {

    this.data = data;
    this.next = null;
}

}

How It Works

Visual representation:

[10] → [20] → [30] → null

Each node knows:

• where the next node exists.

*2. Why Use Linked Lists?
*
Unlike arrays:

• linked lists do NOT require contiguous memory.

This gives:

• dynamic size
• flexible insertion/deletion

Advantages

Dynamic Size

Linked list can grow/shrink easily.

Fast Insert/Delete

If reference is available:

O(1) insertion/deletion

Better Memory Usage

No fixed-size allocation.

3. Drawbacks of Linked Lists
Slow Access

To reach an element:

• traverse node by node.

Complexity:

O(n) access

Extra Memory

Every node stores an additional pointer.

Not Cache Friendly

Nodes are scattered in memory.

Linked Lists trade:

• fast access

for:

• flexible insertion & deletion.

That’s why they are useful in:

• stacks
• queues
• graph structures
• hash tables
• Linked list = chain of nodes
• Nodes store data + next reference
• Dynamic structure
• Slower random access

Linked Lists may seem simple…

But they form the foundation of many advanced data structures

For More Learning: https://www.quipoin.com/tutorial/data-structure-with-java/linked-list-introduction