A link list is a type of data structure that organizes elements in a linear manner. It is composed of nodes, where each node contains both data and a reference to the next node in the sequence. In this article, we will dive deep into link lists and understand how they work, using examples to illustrate their functionality.
What is a Link List?
A link list, also known as a linked list, is a dynamic data structure that allows efficient insertion and deletion operations. Unlike arrays, which have a fixed size, link lists can grow or shrink as needed. Each node in the link list holds data and a pointer or reference to the next node.
Types of Link Lists:
There are different types of link lists based on their organization and functionality. Let’s take a look at three commonly used types:
1. Singly Linked List: In this type of link list, each node contains data and a reference to the next node. The last node points to null, indicating the end of the list.
2. Doubly Linked List: Similar to the singly linked list, each node in the doubly linked list has data and two references – one pointing to the next node and another pointing to the previous node.
3. Circular Linked List: In this type of link list, the last node points back to the first node instead of null, creating a circular structure.
Link List Example:
Let’s consider an example of a singly linked list containing names:
“`html
class Node {
constructor(data) {
this.data = data;
this.next = null;
}
}
class LinkedList {
constructor() {
this.head = null;
}
insert(data) {
const newNode = new Node(data);
if (this.head === null) {
this.head = newNode;
} else {
let current = this.head;
while (current.next !== null) {
current = current.next;
}
current.next = newNode;
}
}
display() {
let current = this.head;
while (current !== null) {
console.log(current.data);
current = current.next;
}
}
}
const myList = new LinkedList();
myList.insert("John");
myList.insert("Jane");
myList.insert("Alice");
myList.display();
“`
In the above example, we define a Node class representing each element in the link list. The LinkedList class contains methods to insert data and display the list. We create a new instance of LinkedList, insert three names, and then display the list.
Advantages of Link Lists:
– Dynamic Size: Link lists can grow or shrink as elements are added or removed.
– Efficient Insertion and Deletion: Insertion and deletion operations are more efficient compared to arrays.
– Faster Operations: Retrieving an element at a specific index may be slower than arrays, but other operations like insertion and deletion are faster.
Limits of Link Lists:
– Random Access: Unlike arrays, link lists do not allow random access to elements. To access an element at a specific index, we need to iterate through the list from the beginning.
– Extra Memory Usage: Each node in the link list requires additional memory for storing references.
In conclusion, link lists are versatile data structures that offer flexibility and efficiency for certain applications. By understanding their types and functionalities, you can leverage link lists to solve various programming challenges.
Now that you have a good understanding of link lists, go ahead and explore their implementation in different programming languages!