### Problem: Linked List Cycle #### Description Given a singly linked list, determine whether the linked list has a cycle (i.e., a node points to one of its previous nodes). #### Problem Statement To solve this problem, you need to write an algorithm that takes the head node of a singly linked list as input and returns a boolean indicating whether the linked list has a cycle. #### Rules and Constraints * The linked list has at least one node. * The linked list is represented as a singly linked structure, where each node contains an integer value and a reference to the next node in the list. * You are not allowed to use any additional data structures other than the linked list itself. * You can assume that the linked list nodes will be non-null. * You need to solve this problem in O(n) time complexity, where n is the number of nodes in the linked list. * You need to solve this problem with O(1) space complexity, which means you should not use any additional variables outside of the space required to store the linked list nodes. #### Expected Output Your algorithm should return a boolean value indicating whether the linked list has a cycle. If the linked list has a cycle, your algorithm should return true. Otherwise, it should return false. ### Example **Input:** {"head":[3,2,0,-4],"pos":1} **Output:** true