ds.java

//Here's a code for inserting a tail in the linked list in java 
//hackerrank solution
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;

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 SinglyLinkedList() {
            this.head = null;
        }

      
    }

    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);
            }
        }
    }
    static SinglyLinkedListNode insertNodeAtTail(SinglyLinkedListNode head, int data) 
    {
        if(head==null)
        {
            head=new SinglyLinkedListNode(data);
        }
        else
        {
        SinglyLinkedListNode temp=head;
        while(temp.next!=null)
        
            temp=temp.next;
        
        temp.next=new SinglyLinkedListNode(data);
        }
        return head;

    }

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

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

        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])?");
        	
          SinglyLinkedListNode llist_head = insertNodeAtTail(llist.head, llistItem);

          llist.head = llist_head;
        }



        printSinglyLinkedList(llist.head, "\n", bufferedWriter);
        bufferedWriter.newLine();

        bufferedWriter.close();

        scanner.close();
    }
}