🔗 Circular Linked Lists Made Simple: A Beginner’s Guide

📌 Introduction

You’ve already explored Singly and Doubly Linked Lists, but there's one more important variant—Circular Linked Lists (CLL). This structure allows the last node to connect back to the first, creating a continuous loop.

In this article, you’ll understand how circular linked lists work, where they’re used, and how to implement them effectively.

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🔍 What is a Circular Linked List?

A Circular Linked List is a variation where the last node points back to the first node, forming a circle.

Variants:

1. Singly Circular Linked List – Last node points to the head node.

2. Doubly Circular Linked List – Last node points to head, and head’s prev points to last.

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🔄 Linear vs Circular Linked List

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💻 Implementation (Singly Circular Linked List in C++)

#include <iostream>
using namespace std;

class Node {
public:
    int data;
    Node* next;

    Node(int value) {
        data = value;
        next = nullptr;
    }
};

void printCircular(Node* head) {
    if (head == nullptr) return;

    Node* temp = head;
    do {
        cout << temp->data << " -> ";
        temp = temp->next;
    } while (temp != head);
    cout << "(back to head)" << endl;
}

int main() {
    Node* head = new Node(10);
    Node* second = new Node(20);
    Node* third = new Node(30);

    head->next = second;
    second->next = third;
    third->next = head; // Circle created

    printCircular(head);

    return 0;
}

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🔧 Operations on Circular Linked List

• Insert at Head or Tail

• Delete a node

• Traversing (special care: don’t go infinite)

• Insertion after a specific node

• Loop detection techniques

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📈 Applications of Circular Linked Lists

• Round-robin scheduling (OS)

• Music playlist rotation

• Multiplayer games turn rotation

• Circular queues

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⚠️ Things to Watch Out For

• Infinite loops if not handled properly

• Traversal logic is slightly different

• Extra conditions in edge cases (like only one node)

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✅ Conclusion

Circular Linked Lists bring efficiency in situations requiring continuous cycling of data. Once mastered, they become extremely useful in real-world applications like operating systems and embedded systems.

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Article 4: Linked List Interview Questions & Answers,

Linked List Operations (Insert/Delete/Reverse)