Chapter 11, Problem 14E

Complete program:

//Import required packages

import java.util.*;

//Definition of class Duplicate

public class Duplicate

{

    //Definition of class main

    public static void main(String[] args)

    {

        //Declare the variable "s" as string

        String s;

        //Create an object for scanner class

        Scanner sc = new Scanner(System.in);

        //Get the string from the user

        System.out.println("Enter the string:");

        //Get the values

        s = sc.next();

        //Call the method "duplicate()"

        String result = duplicate(s);

        //Print the vowel count

System.out.println("Duplicated string is: " + result);

    }

    //Definition of method "duplicate()"

    public static String duplicate(String s)

    {

        //Declare the variable "res"

        String res;

        //Check whether the string length is 0

        if (s...