# What Is the Linked List in Data Structure?

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Scott Campbell

The linked list is a fundamental data structure used in computer science and programming. It is a dynamic data structure that allows for efficient insertion and deletion of elements. In this article, we will explore what a linked list is, how it works, and its advantages and disadvantages.

## What Is a Linked List?

A linked list is a collection of nodes, where each node contains two parts: data and a reference (or pointer) to the next node in the sequence. The first node is called the head, and the last node points to null, indicating the end of the list.

The basic structure of a node in a singly linked list looks like this:

```    ```<pre>
struct Node {
int data;
Node* next;
};
</pre>```
```

In this example, each node contains an integer value as its data and a pointer to the next node in the sequence.

## How Does It Work?

In a linked list, each node holds both data and a reference to the next node. By following these references, we can traverse through all the elements in the list.

To access an element at a specific position in the linked list, we must start from the head node and iterate through each subsequent node until we reach our desired position. This process is known as traversal.

### Insertion

One of the main advantages of using a linked list is its ability to efficiently insert elements. To insert an element at any given position:

• Create a new node with the desired data.
• Update the next pointer of the new node to point to the next node in the sequence.
• Update the next pointer of the previous node to point to the new node.

This process allows for constant-time insertion at both the beginning and end of the linked list. However, inserting at a specific position requires traversal, resulting in a time complexity of O(n).

### Deletion

Similar to insertion, deleting an element from a linked list can be done efficiently. To delete an element:

• Find the previous node of the node to be deleted.
• Update the next pointer of the previous node to skip over the node to be deleted.
• Delete the desired node.

This process also allows for constant-time deletion at both ends of the linked list but requires traversal for deleting at a specific position.

• Dynamic Size: Unlike arrays, linked lists can grow or shrink dynamically without requiring pre-allocation or wasting memory.
• Efficient Insertion and Deletion: Adding or removing elements from a linked list is efficient compared to arrays, especially when dealing with large data sets.