CycleDetection.js

/**
 * A LinkedList based solution for Detecting a Cycle in a list.
 * https://en.wikipedia.org/wiki/Cycle_detection
 */

function detectCycle (head) {
 /*
 Problem Statement:
 Given head, the head of a linked list, determine if the linked list has a cycle in it.
 Link for the Problem: https://leetcode.com/problems/linked-list-cycle/
 */
 if (!head) { return false }

 let slow = head
 let fast = head.next
 while (fast && fast.next) {
 if (fast === slow) { return true }
 fast = fast.next.next
 slow = slow.next
 }
 return false
}

export { detectCycle }