Detecting a Loop in a Singly Linked List

Detecting a Loop in a Singly Linked List

Problem:
Given a singly linked list, find if there exist a loop.

Solution:

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bool hasLoop(ListNode head) {   ListNode slow = head, fast = head;   while (slow != null && fast != null && fast.next != null) {     slow = slow.next;     fast = fast.next.next;     if (slow == fast)       return true;   }   return false; }