Find length of loop

//Find length of loop

import java.io.*;
import java.util.*;

class Node {
    int data;
    Node next;

    Node(int x) {
        data = x;
        next = null;
    }
}

public class LinkedList {
    public static void printList(Node node) {
        while(node != null) {
            System.out.print(node.data + " ");
            node = node.next;
        }
        System.out.println();
    }

    public static void makeLoop(Node head, Node tail, int x) {
        if(x == 0) {
          return;
        }

        Node curr = head;

        for(int i = 1; i < x; i++) {
          curr = curr.next;
        }

        tail.next = curr;
    }

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int t = Integer.parseInt(br.readLine());

        while(t-- > 0) {
            ArrayList<Integer> arr = new ArrayList<>();
            String input = br.readLine();
            StringTokenizer st = new StringTokenizer(input);

            while(st.hasMoreTokens()) {
                arr.add(Integer.parseInt(st.nextToken()));
            }

            int k = Integer.parseInt(br.readLine());
            Node head = new Node(arr.get(0));
            Node tail = head;

            for(int i = 1; i < arr.size(); ++i) {
                tail.next = new Node(arr.get(i));
                tail = tail.next;
            }

            makeLoop(head, tail, k);
            Solution ob = new Solution();
            System.out.println(ob.countNodesinLoop(head));
        }
    }
}

class Node {
    int data;
    Node next;
    Node(int d) {data = d; next = null; }
}

class Solution {
    public int countNodesinLoop(Node head) {
        Node slowp = head;
        Node fastp = head;
        int count = 0;
        
        while(fastp != null && fastp.next != null) {
            slowp = slowp.next;
            fastp = fastp.next.next;
            
            if(slowp == fastp) {
                count = 1;
                
                while(slowp.next != fastp) {
                    count++;
                    slowp = slowp.next;
                }
                
                break;
            }
        }
        
        return count;
    }
}