Detect Cycle in Linked List

A singly linked list of N nodes (indices 0 .. N-1) is described. The tail's next pointer either points at the node with index pos, forming a cycle, or is null (given as pos = -1). Determine whether the list contains a cycle.

Input Format

The first line contains an integer N. The second line contains N space-separated integers, the node values (empty if N is 0). The third line contains an integer pos: the index the tail links back to, or -1 for no cycle.

Output Format

Print 1 if the list contains a cycle, otherwise print 0.