1class Solution {2    public ListNode detectCycle(ListNode head) {3        ListNode slow = head, fast = head;4        while (fast != null && fast.next != null) {5            slow = slow.next;6            fast = fast.next.next;7            if (slow == fast) {8                ListNode finder = head;9                while (finder != slow) {10                    finder = finder.next;11                    slow = slow.next;12                }13                return finder;14            }15        }16        return null;17    }18}