# 1. Introduction

A common problem with linked lists is the potential for a cycle, where a node references an earlier node in the sequence, creating an infinite loop. Detecting such a cycle is essential for preventing infinite loops in operations that traverse the linked list. In this guide, we will walk through the implementation of an algorithm, known as Floyd's cycle-finding algorithm, or the "Tortoise and the Hare" technique, to detect a cycle in a linked list.

# 2. Program Overview

1. Define the Node class for linked list nodes.

3. Use the "Tortoise and the Hare" technique to detect a cycle.

# 3. Code Program

``````class Node {
constructor(value) {
this.value = value;
this.next = null;
}
}

constructor() {
}

// Function to add a node to the end of the linked list
let newNode = new Node(value);
return;
}
while (current.next) {
current = current.next;
}
current.next = newNode;
}

// Function to check for a cycle in the linked list
hasCycle() {
return false;
}
let slow = this.head; // the tortoise
let fast = this.head.next; // the hare

while (fast && fast.next) {
if (fast === slow) {
return true; // cycle detected
}
slow = slow.next;
fast = fast.next.next;
}
return false;
}
}

// Example

// Intentionally create a cycle for demonstration

console.log(list.hasCycle()); // Outputs: true
``````

# 4. Step By Step Explanation

1. Node Class: This represents individual elements in our linked list. Each node contains a value and a reference to the next node.