Understanding Linked Lists in C++: A Detailed Guide for You
Linked lists are a fundamental data structure in computer science, and C++ provides robust tools to implement them. If you’re new to linked lists or looking to enhance your understanding, this guide is tailored just for you. Let’s delve into the intricacies of linked lists in C++.
What is a Linked List?
A linked list is a linear collection of data elements, called nodes, each pointing to the next node by means of a pointer. Unlike arrays, linked lists do not store elements in contiguous memory locations. Instead, each node contains the data and a reference (or pointer) to the next node in the sequence.
Types of Linked Lists
There are several types of linked lists, each with its unique characteristics:
| Type | Description |
|---|---|
| Singly Linked List | Each node contains a data field and a reference to the next node in the sequence. |
| Doubly Linked List | Each node contains a data field and two references: one to the next node and one to the previous node. |
| Circular Linked List | Similar to a singly linked list, but the last node points back to the first node, forming a circle. |
| Doubly Circular Linked List | Combination of doubly linked list and circular linked list, where the last node points back to the first node. |
Implementing a Singly Linked List in C++
Let’s start by implementing a singly linked list in C++. We’ll create a Node structure and a LinkedList class to manage the nodes.
struct Node { int data; Node next; Node(int val) : data(val), next(nullptr) {}};class LinkedList {public: Node head; LinkedList() : head(nullptr) {} void insert(int value) { Node newNode = new Node(value); newNode->next = head; head = newNode; } void display() { Node temp = head; while (temp != nullptr) { std::cout << temp->data << " "; temp = temp->next; } std::cout << std::endl; }};
Adding Functionality to the LinkedList
Now that we have a basic singly linked list, let's add some functionality to it, such as searching for a value, deleting a node, and reversing the list.
void LinkedList::search(int value) { Node temp = head; while (temp != nullptr) { if (temp->data == value) { std::cout << "Value found: " << value << std::endl; return; } temp = temp->next; } std::cout << "Value not found." << std::endl;}void LinkedList::deleteNode(int value) { Node temp = head; Node prev = nullptr; while (temp != nullptr && temp->data != value) { prev = temp; temp = temp->next; } if (temp == nullptr) { std::cout << "Value not found." << std::endl; return; } if (prev == nullptr) { head = temp->next; } else { prev->next = temp->next; } delete temp;}void LinkedList::reverse() { Node prev = nullptr; Node current = head; Node next = nullptr; while (current != nullptr) { next = current->next; current->next = prev; prev = current; current = next; } head = prev;}
Using the LinkedList
Now that we have a fully functional linked list, let's see how to use it in a program.
int main() { LinkedList list; list.insert(10); list.insert(20); list.insert(30); list.insert(40); list.display(); // Output: 40 30 20 10 list.search(30); // Output: Value found: 30 list.deleteNode(20); list.display(); // Output:
