Lecture 135:- LL Class - 1

It seems like you're referring to "Linked List" (LL) and are requesting information about its basics. Let's delve into the fundamentals of a Linked List.

Linked List: A linked list is a linear data structure where elements, known as nodes, are connected together using pointers. Each node contains both data and a reference (or pointer) to the next node in the sequence. The last node typically points to a null reference to indicate the end of the list.

Advantages of Linked List:

1. Dynamic Size: Linked lists can grow or shrink dynamically without the need for resizing.
2. Efficient Insertions and Deletions: Adding or removing elements from a linked list is efficient as long as you have a reference to the node.
3. Memory Allocation: Linked lists can use memory more flexibly than arrays, as memory is allocated individually for each node.

Disadvantages of Linked List:

1. Access Time: Accessing an element at a specific index requires traversing the list from the beginning.
2. More Memory Overhead: Each node requires extra memory for storing the pointer, leading to increased memory usage compared to arrays.

Types of Linked List:

1. Singly Linked List: Each node points to the next node in the list.
2. Doubly Linked List: Each node points to both the next and the previous nodes, allowing bidirectional traversal.
3. Circular Linked List: The last node points back to the first node, creating a circular structure.

Here's a basic implementation of a singly linked list in C++:

cppCopy code

#include <iostream> class Node { public: int data; Node* next; Node(int value) : data(value), next(nullptr) {} }; class LinkedList { private: Node* head; public: LinkedList() : head(nullptr) {} void insert(int value) { Node* newNode = new Node(value); newNode->next = head; head = newNode; } void display() { Node* current = head; while (current != nullptr) { std::cout << current->data << " "; current = current->next; } std::cout << std::endl; } }; int main() { LinkedList list; list.insert(3); list.insert(7); list.insert(12); list.display(); // Output: 12 7 3 return 0; }

In this example, a basic singly linked list is implemented with an insert method to add elements at the beginning and a display method to print the list.

This is just an introductory example. Linked lists can be extended with various operations like inserting at specific positions, deleting elements, reversing the list, merging, and more. Understanding linked lists is essential as they serve as a foundation for more complex data structures and algorithms.