import java.util.;
/*

  • Definition for singly-linked list.
  • class ListNode {
  • int val;
  • ListNode next;
  • ListNode(int x) {
  • val = x;
  • next = null;
  • }
  • }
  • /
    public class Solution {
    public boolean hasCycle(ListNode head) {
      List list = new ArrayList<ListNode>();
  while(head!=null){
      if(list.contains(head)){
          return true;
      }else{
          list.add(head);
          head=head.next;
      }
  }
  return false;
    }
    }