Advantages And Disadvantages Of Linked Lists Summed Up For You!

In Python, a list is an ordered sequence of values that can be of any type-string, integer, float, etc.  It is a non-scalar type Data Structure. All the elements of a list are enclosed in square brackets, separated by commas. Elements in a list are arranged in a sequence beginning with index 0, just like characters in strings. 

Now those who are well-versed with Data Structures in Python know that stacks allow insertion and deletion of objects at one end while, in queues, new objects are inserted at one end and deletion takes from the other end. Well, there exists a more flexible data structure called a linked list that allows the insertion and deletion of an object at an arbitrary position.

Lets' discuss the advantages and disadvantages of linked lists:

What are linked lists?

A linked list is a sequence of objects called nodes. The relative position of the objects in a linked list is maintained using the next link. Thus, a linked list comprises a number of objects, each of which contains a link to the next object (node). 

For example:

Let us examine the link 1st as shown in the figure above. The first node of the linked list comprises an int object 20 and a next link, which is a reference to the second node in the linked list. In a similar manner, the second node consists of an int object 15 and the next link which in turn is the reference to the third node, and there is no next object ahead of it. Hence, it has an int object 25 and the next link refers to None.

We describe a class Node for dealing with the nodes of a linked list in a program. An instance of this class comprises two members, namely, data and next. A linked list may require the below mentioned functionalities:

• Creating an empty linked list
• Inserting a node at the beginning of a linked list
• Deleting a node from the beginning of the linked list
• Deleting a node with a particular value from the linked list
• Inserting a node in a sorted linked list

Let's now proceed to discuss the advantages of linked lists over other Data Structures in Programming languages.

What are the advantages of Linked lists?

1) Dynamic growth/shrinkage

A linked list grows or shrinks dynamically depending upon how many items you want to add to your linked list. You don't have to specify its length initially. This makes them very useful when working with large amounts of data. For example, if you want to store names of people in a database then you will not have to worry about specifying their lengths because they would automatically increase according to the amount of information added.

2) Easy implementation

Data structures like stacks and queues can be easily implemented using linked lists. For example: In Python, stack implementation of linked list, push and pop operations are analogous to the following operations in a linked list: insertion at the beginning and deletion from the beginning. In queue implementation of the linked list, the method enqueue is used to insert at the rear end of the linked queue while the method dequeue deletes from the front end of the linked queue.

3) No space overhead

Since linked lists do not use any additional storage area apart from what is required by the actual elements themselves, they provide better performance than arrays. Also, unlike arrays, linked lists are dynamic meaning that we cannot predict beforehand how much memory will be needed. Therefore, we should always allocate enough memory before creating our linked list. If we try to create a linked list without allocating sufficient memory, we might get out of bounds exception.

4) Easy insertion and deletion

It's really simple to insert and remove the nodes. We don't have to move elements after they are added or removed, which is unlike what happens in Arrays. In the linked list, we only have to update the address at the next point of nodes.

What are the disadvantages of linked lists?

1) More consumption of memory