ques6.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 'getNode' function below.
     *
     * The function is expected to return an INTEGER.
     * The function accepts following parameters:
     *  1. INTEGER_SINGLY_LINKED_LIST llist
     *  2. INTEGER positionFromTail
     */

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

    public static int getNode(SinglyLinkedListNode llist, int positionFromTail) {
    // Write your code here
    SinglyLinkedListNode currnode=llist;
    int n=0;
    while(currnode!=null){
        n++;
        currnode=currnode.next;
        
    }
    currnode=llist;
    n=n-1-positionFromTail;
    for(int i=0;i<n;i++){
        currnode=currnode.next;
    }
    return currnode.data;

    }

}

public class ques6 {
    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")));

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

        IntStream.range(0, tests).forEach(testsItr -> {
            try {
                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 position = Integer.parseInt(bufferedReader.readLine().trim());

                int result = Result.getNode(llist.head, position);

                bufferedWriter.write(String.valueOf(result));
                bufferedWriter.newLine();
            } catch (IOException ex) {
                throw new RuntimeException(ex);
            }
        });

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