public class HasCycle {

public static boolean hasCycle(ListNode head) {

ListNode start;

ListNode runner;

if (head ==null || head.next == null){

return false;

}

if (head.next.next != null){

start = head;

runner = head.next.next;

}else{

return false;

}

while (runner != null){

if (start.val == runner.val){

return true;

}

start = start.next;

if (runner.next == null){

return false;

}

runner = runner.next.next;

}

return false;

}

public static void main(String args[]){

ListNode n = null;

System.out.print(HasCycle.hasCycle(n));

}

}