LeetCode Algorithm Challenges: Linked List Cycle

Question

Given , the head of a linked list, determine if the linked list has a cycle in it.

There is a cycle in a linked list if there is some node in the list that can be reached again by continuously following the pointer. Internally, is used to denote the index of the node that tail's pointer is connected to. Note that is not passed as a parameter.

Return if there is a cycle in the linked list. Otherwise, return .