Data Structures - Full Course Using C and C++

Introduction

This tutorial provides a comprehensive overview of essential data structures implemented in C and C++. It is designed for learners who have a basic understanding of pointers in C. Throughout this guide, we will explore various data structures, their implementations, and practical applications, making it easier for you to grasp these concepts and apply them in your programming projects.

Step 1: Understanding Data Structures

• Data structures are ways to organize and store data for efficient access and modification.
• Key types include:
  • Lists
  • Stacks
  • Queues
  • Trees
  • Graphs

Step 2: Exploring Lists as Abstract Data Types

• Lists are collections that hold elements in a specific order.
• Key characteristics:
  • Can be implemented using arrays or linked lists.
  • Support dynamic resizing and efficient insertion/deletion.

Step 3: Introduction to Linked Lists

• Linked lists consist of nodes, where each node contains data and a pointer to the next node.
• Advantages over arrays:
  • Dynamic size
  • Efficient insertions and deletions

Step 4: Comparing Arrays and Linked Lists

• Arrays:
  • Fixed size
  • Fast access using indices
• Linked Lists:
  • Dynamic size
  • Slower access (requires traversal)

Step 5: Implementing Linked Lists in C/C++

• Create a node structure:

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

• Basic operations:
  • Inserting a node
  • Deleting a node
  • Traversing the list

Step 6: Inserting Nodes

• At the beginning:

  void insertAtBeginning(Node** head_ref, int new_data) {
      Node* new_node = (Node*)malloc(sizeof(Node));
      new_node->data = new_data;
      new_node->next = (*head_ref);
      (*head_ref) = new_node;
  }
  

• At nth position:
  • Traverse to the nth node and adjust pointers.

Step 7: Deleting Nodes

• To delete a node at nth position:
  • Traverse to the node just before the nth node and adjust pointers.

Step 8: Reversing a Linked List

• Iterative method:
  • Use three pointers to reverse the links between nodes.
• Recursive method:
  • Recursively reverse the list and adjust pointers.

Step 9: Introduction to Doubly Linked Lists

• Each node contains two pointers: one to the next node and one to the previous node.
• Allows traversal in both directions, making certain operations easier.

Step 10: Implementing Stacks

• Stack can be implemented using:
  • Arrays
  • Linked lists
• Key operations include:
  • Push
  • Pop
  • Peek

Step 11: Using Stacks for Practical Applications

• Reverse a string or linked list.
• Check for balanced parentheses in expressions.

Step 12: Understanding Queues

• Queues are FIFO (First In, First Out) structures.
• Implemented using:
  • Arrays
  • Linked lists
• Key operations include:
  • Enqueue
  • Dequeue

Step 13: Introduction to Trees

• Trees consist of nodes with parent-child relationships.
• Binary trees and binary search trees (BST) are key types.

Step 14: Implementing Binary Search Trees

• Each node has at most two children, with the left child being smaller and the right being larger.
• Key operations:
  • Insert
  • Delete
  • Traverse (Preorder, Inorder, Postorder)

Step 15: Introduction to Graphs

• Graphs consist of nodes (vertices) connected by edges.
• Represented using:
  • Edge lists
  • Adjacency matrices
  • Adjacency lists

Conclusion

This guide covers essential data structures implemented in C and C++. By understanding linked lists, stacks, queues, trees, and graphs, you will improve your programming skills and be better equipped for technical challenges. For next steps, consider practicing these implementations and exploring more advanced data structures and algorithms.