Q1]

import java.util.Scanner;

class VowelPrinter extends Thread {
    private String input;

    public VowelPrinter(String input) {
        this.input = input;
    }

    @Override
    public void run() {
        for (char ch : input.toCharArray()) {
            if (isVowel(ch)) {
                System.out.println(ch);
                try {
                    Thread.sleep(3000); // Sleep for 3 seconds
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    private boolean isVowel(char ch) {
        ch = Character.toUpperCase(ch);
        return ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U';
    }
}

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter a string: ");
        String input = scanner.nextLine();

        VowelPrinter printer = new VowelPrinter(input);
        printer.start();

        scanner.close();
    }
}


Q2]

import java.util.*;

public class StudentNames {
    public static void main(String[] args) {
  
        if (args.length == 0) {
            System.out.println("Usage: java StudentNames <name1> <name2> ... <nameN>");
            return;
        }

       
        List<String> studentNames = new ArrayList<>();

 
        for (String name : args) {
            studentNames.add(name);
        }

        
        System.out.println("Student Names (using Iterator):");
        Iterator<String> iterator = studentNames.iterator();
        while (iterator.hasNext()) {
            System.out.println(iterator.next());
        }

      
        System.out.println("\nStudent Names (in reverse order using ListIterator):");
        ListIterator<String> listIterator = studentNames.listIterator(studentNames.size());
        while (listIterator.hasPrevious()) {
            System.out.println(listIterator.previous());
        }
    }
}