What is a linked list?

Imagine you're standing in line at your favorite coffee shop, eagerly awaiting your turn. In one scenario, you have a numbered ticket representing your place in line - this is similar to how arrays work. Each person has a fixed position, just like each element in an array.

Now, picture a different scenario: instead of a numbered ticket, you receive a special message, "You're next!" without knowing how many people are ahead of you. You can now relax, grab a coffee, and go about your day until it's your turn - that's like being a node in a linked list .

Key points about linked list elements:

• They contain data and a pointer to the next

• Each element, or node, holds both data and a reference to the next node in the sequence.

• They are not stored in contiguous location as array elements

Data and pointer together is a node, and linked list is a chain of nodes.

Why it matters?

Imagine someone cutting in line at the coffee shop. In this scenario, if someone cuts in, all the numbered tickets after this person would have to be destroyed, and new ones issued to everyone in line, causing chaos and inconvenience.

However, in a linked list, if someone cuts in, they can simply be redirected to the appropriate place in line by changing the 'pointer' in front of and behind this person without disrupting the entire queue.

This ability to efficiently handle changes in data structure is one of the key advantages of linked lists, making them invaluable in scenarios where data is frequently added, removed, or rearranged.

What gets easier?

If you insert or delete an element in an array, you've got trouble. All the elements that come after this element would need to change their index because arrays store elements contiguously. The worst-case time complexity is O(n). However, a linked list makes it easier by simply changing the pointers before and after that element, resulting in a time complexity of O(1).

What gets harder?

If you look up an element in an array, you'll only need to know the index of that element, which makes the time complexity O(1). However, in a linked list, you don't have an "index," so you need to loop through the entire list to find that element. The worst-case scenario is O(n).

Types of linked lists:

The types of linked lists come from the following guessing game:

• Who's the first in line?

• Who's the person in front of you?

• Who's the person behind you?

• Who's the last person in line?

• Can I pass the message to the next person or the person in front of me or both?

The three types of linked lists answer those questions:

• Singly Linked List: People holding hands in a single line.

• Doubly Linked List: People holding hands in both directions.

• Circular Linked List: People holding hands in a circle, with the last person connected to the first person.

Conclusion

In summary, linked lists are like a lovely assistant at your favorite coffee shop, helping organize the queue smoothly. Unlike arrays, where everyone's spot is fixed with numbered tickets, linked lists offer a more flexible approach. Picture getting a special message when it's your turn instead of relying on a fixed order. If someone tries to jump the line, linked lists handle it by adjusting pointers, much like the assistant redirecting the person to their right place. While linked lists excel at adding and removing people from the queue, finding someone might take a bit more time than in arrays. But by understanding these differences, developers can choose the best option for their needs, ensuring efficient data management in their applications.