ques4.java

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

class SinglyLinkedListNode {
    public int data;
    public SinglyLinkedListNode next;

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

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;
    }
}

class SinglyLinkedListPrintHelper {
    public static void printList(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);
            }
        }
    }
}

class Result {

    /*
     * 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;
     * }
     *
     */

    public static SinglyLinkedListNode insertNodeAtPosition(SinglyLinkedListNode llist, int data, int position) {
        SinglyLinkedListNode newnode=new SinglyLinkedListNode(data);
        SinglyLinkedListNode currnode=llist;
        int n=0;
        while(n<position-1){
            currnode=currnode.next;
            n++;
        }
        newnode.next=currnode.next;
        currnode.next=newnode;
        return llist;
    
    // Write your code here

    }

}

public class ques4 {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        SinglyLinkedList llist = new SinglyLinkedList();

        int llistCount = Integer.parseInt(bufferedReader.readLine().trim());

        IntStream.range(0, llistCount).forEach(i -> {
            try {
                int llistItem = Integer.parseInt(bufferedReader.readLine().trim());

                llist.insertNode(llistItem);
            } catch (IOException ex) {
                throw new RuntimeException(ex);
            }
        });

        int data = Integer.parseInt(bufferedReader.readLine().trim());

        int position = Integer.parseInt(bufferedReader.readLine().trim());

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

        SinglyLinkedListPrintHelper.printList(llist_head, " ", bufferedWriter);
        bufferedWriter.newLine();

        bufferedReader.close();
        bufferedWriter.close();
    }
}