Insert a node at a specific position in a linked list

InsertNodeToLinkedList.java

package com.company;

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

public class Solution {

    static class SinglyLinkedListNode {
        public int data;
        public SinglyLinkedListNode next;

        public SinglyLinkedListNode(int nodeData) {
            this.data = nodeData;
            this.next = null;
        }
    }

    static class SinglyLinkedList {
        public SinglyLinkedListNode head;
        public SinglyLinkedListNode tail;

        public SinglyLinkedList() {
            this.head = null;
            this.tail = null;
        }

        public void insertNode(int nodeData) {
            SinglyLinkedListNode node = new SinglyLinkedListNode(nodeData);

            if (this.head == null) {
                this.head = node;
            } else {
                this.tail.next = node;
            }

            this.tail = node;
        }
    }

    public static void printSinglyLinkedList(SinglyLinkedListNode node, String sep, BufferedWriter bufferedWriter) throws IOException {
        while (node != null) {
            bufferedWriter.write(String.valueOf(node.data));

            node = node.next;

            if (node != null) {
                bufferedWriter.write(sep);
            }
        }
    }

    /*
     * Complete the 'insertNodeAtPosition' function below.
     *
     * The function is expected to return an INTEGER_SINGLY_LINKED_LIST.
     * The function accepts following parameters:
     *  1. INTEGER_SINGLY_LINKED_LIST llist
     *  2. INTEGER data
     *  3. INTEGER position
     */

    /*
     * For your reference:
     *
     * SinglyLinkedListNode {
     *     int data;
     *     SinglyLinkedListNode next;
     * }
     *
     */

    static SinglyLinkedListNode insertNodeAtPosition(SinglyLinkedListNode llist, int data, int position) {
        // Write your code here

        SinglyLinkedListNode copy = llist;
        SinglyLinkedListNode toIns = new SinglyLinkedListNode(data);
        if (position == 0) {
            toIns.next = copy;
            return toIns;
        }
        int pos = 0;
        System.out.println("position:" + position);
        boolean shouldC=true;
        while (shouldC) {
            System.out.println(pos);
            if (pos == position) {
                System.out.println("End:");
                SinglyLinkedListNode toRep = new SinglyLinkedListNode(copy.data);
                toRep.next=copy.next;
                copy.data = toIns.data;
                copy.next = toRep;
                shouldC=false;
                return llist;
            } else {
                if (copy.next != null) {
                    copy = copy.next;
                } else {
                    shouldC=false;
                }

            }
            pos++;
        }
        return llist;

    }


    private static final Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) throws IOException {
        BufferedWriter bufferedWriter = null;
        try {
            File f = new File("s.txt");
            if (!f.exists()) {
                System.out.println(f.createNewFile());

            }
            bufferedWriter = new BufferedWriter(new FileWriter(f.getName()));
        } catch (IOException e) {
            e.printStackTrace();
        }

        SinglyLinkedList llist = new SinglyLinkedList();

        int llistCount = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        for (int i = 0; i < llistCount; i++) {
            int llistItem = scanner.nextInt();
            scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

            llist.insertNode(llistItem);
        }

        int data = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        int position = scanner.nextInt();
        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");

        SinglyLinkedListNode llist_head = insertNodeAtPosition(llist.head, data, position);

        printSinglyLinkedList(llist_head, " ", bufferedWriter);
        bufferedWriter.newLine();

        bufferedWriter.close();

        scanner.close();
    }
}