141. Linked List Cycle

Runtime   0 ms
Beats     100%


Memory    43.6 MB
Beats     52.88%


public class Solution {
    public boolean hasCycle(ListNode head) {
        if(head == null)return false;

        ListNode slow = head;
        ListNode fast = head;

        while(fast != null && fast.next!= null)
        {
            fast = fast.next.next;
            slow = slow.next;
            if(fast == slow)return true;
        }

        return false;
    }
}