print-the-elements-of-a-linked-list-in-reverse.java

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;

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) {
        while (node != null) {
            System.out.print(node.data);

            node = node.next;

            if (node != null) {
                System.out.print(sep);
            }
        }
    }
}

class Result {

    /*
     * Complete the 'reversePrint' function below.
     *
     * The function accepts INTEGER_SINGLY_LINKED_LIST llist as parameter.
     */

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

    public static void reversePrint(SinglyLinkedListNode llist) {
        if (llist.next != null) {
            reversePrint(llist.next);
        }
        System.out.println(llist.data);
    }

}

public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

        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);
                    }
                });

                Result.reversePrint(llist.head);
            } catch (IOException ex) {
                throw new RuntimeException(ex);
            }
        });

        bufferedReader.close();
    }
}