# Is Single Linked List a Linear Data Structure?

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Heather Bennett

Is Single Linked List a Linear Data Structure?

A linked list is a common data structure used in computer science and programming. It is a collection of nodes, where each node contains both data and a reference (or link) to the next node in the sequence.

There are different types of linked lists, such as singly linked lists, doubly linked lists, and circular linked lists. In this article, we will focus on the single linked list and explore whether it can be considered a linear data structure.

## What is a Linear Data Structure?

Before diving into the discussion about whether single linked lists are linear data structures, let’s first understand what linear data structures are. A linear data structure is a collection of elements where each element has a unique predecessor and successor, except for the first element (which has no predecessor) and the last element (which has no successor). The order of elements in these structures is significant as it defines their position within the structure.

## The Structure of Single Linked Lists

In a single linked list, each node contains two parts: the data part and the next pointer part. The data part holds the actual value or information stored in that node, while the next pointer part contains the address (or reference) to the next node in the sequence.

Example:

• Node 1: Data = 10 | Next = 1001
• Node 2: Data = 20 | Next = 1002
• Node 3: Data = 30 | Next = NULL

In this example, Node 1 contains the value 10 and its next pointer points to Node 2 (addressed as ‘1001’). Node 2 contains the value 20 and its next pointer points to Node 3 (addressed as ‘1002’). Node 3 contains the value 30, and since it is the last node in the list, its next pointer is set to NULL.

## The Linearity of Single Linked Lists

Now let’s address the question: Is a single linked list a linear data structure? The answer is yes.

Although the nodes in a single linked list are not stored in contiguous memory locations like arrays, they still follow a specific order. Each node has a direct link to its successor, except for the last node which points to NULL.

Therefore, we can traverse through a single linked list starting from the first node (also known as the head), following each next pointer until we reach the last node. This linear traversal allows us to access or modify elements in a sequential manner.

However, it’s important to note that while single linked lists are considered linear data structures, they do not provide constant-time access to arbitrary elements like arrays do. In order to access an element at a specific position in a single linked list, we need to traverse through all the preceding nodes until we reach our desired position. This makes their time complexity for accessing elements O(n), where n is the number of nodes in the list.

## Conclusion

In conclusion, single linked lists can be categorized as linear data structures due to their inherent order and sequential traversal capabilities. They offer efficient insertion and deletion operations at both ends of the list but have slower access times compared to arrays when accessing specific elements.

By understanding and utilizing different data structures like single linked lists, programmers can optimize their algorithms and solve problems more effectively.