Linked List Implementation in C/C++

Introduction

• Previous Lessons: Covered the operations and compared Linked List and Arrays.
• Today's Lesson: Implementing Linked List in C and C++.
• Prerequisites: Knowledge of pointers and dynamic memory allocation in C/C++.
• Resources: Check the video description for additional materials.

Linked List Basics

• Structure: Data is stored in non-contiguous blocks of memory called nodes.
• Node Components: Each node has two fields:
  • Data
  • Address of the next node (link)
• Example: Linked List with nodes having addresses 200, 100, and 300.
  • First node address part: 100
  • Second node address part: 200
  • Third node address part: null (0, an invalid address)

Identity of the Linked List

• Head Node: Pointer to the first node, serves as the identity of the linked list.
• Pointer Variable: Can be named (e.g., A for simplicity).

Defining the Node Structure in C/C++

• Structure Definition in C:

  struct node {
    int data;
    struct node* next;
  };
  

• Name Convention: next can be any valid name (like link or next).
• C++ Syntax:

  struct Node {
    int data;
    Node* next;
  };
  

Creating and Initializing the Linked List

• Pointer Declaration: Declare a pointer to the head node.

  Node* A = nullptr;
  

• Create and Insert First Node:
  • Create memory using malloc (C) or new (C++).
  • C:

    Node* temp = (Node*)malloc(sizeof(Node));
    

  • C++:

    Node* temp = new Node();
    

  • Fill Data and update links:

    temp->data = 2;
    temp->next = nullptr;
    A = temp;
    

  • Prefer using new in C++.

Inserting Nodes in Non-Empty List

• Insertion Strategies:
  • Beginning, End, or Middle of the list.
  • Specialized functions will be implemented in future lessons.
• Example to Insert at the End:
  • Create another node:

    Node* temp = new Node();
    temp->data = 4;
    temp->next = nullptr;
    

  • Traverse to the end:

    Node* temp1 = A;
    while (temp1->next != nullptr) {
      temp1 = temp1->next;
    }
    temp1->next = temp;
    

  • Repeat to insert another node with value 6.

Summary

• Initialization: Start with an empty list by setting the head node's pointer to null.
• Node Insertion: Create a node, assign data, adjust links, and update pointers.
• Traversing the List: Use a temporary pointer to navigate through the list to find the right position.
• Future lessons will cover more advanced insertions and other list operations in detail.

Thank you for watching!