Question

Write a Java program that prompts the user to input a word (String).

The program must print the reversed word with all consecutive duplicate characters removed.

The program must contain the following classes: -

The StackX class (you can use the Java Stack class). - The Reverse class which must contain a private data field called “word” of type string, a constructor, and a void method called revNoDup(). The revNoDup() method must reverse the word and remove the consecutive duplicate characters. The revNoDup() method must print the new word (i.e. reversed with consecutive duplicate characters removed). The revNoDup() method must use a Stack to reverse the word and remove the duplicate characters. - The Test class which must contain the main() method. In the main() method, you must prompt the user to input a word (String), create an object from class Reverse, and call the revNoDup() method.

Here is a sample run:

Enter a word:

Tomorrow

woromoT

Answer 1

import java.io.*; 
import java.util.*; 
//Declaring class Stack
public class StackX {
        public static void main(String[] args) {
                String str;
                Scanner scan = new Scanner(System.in);
                System.out.print("Enter a word: ");
                str = scan.nextLine();
                //Object reference fror Reverse class
                Reverse reverse = new Reverse(str);
                reverse.revNoDup();
        }
}
class Reverse{
        //Private variable word
        private String word;
        //Parameterized constructor
        public Reverse(String str) {
                word=str;
        }
        //Void method
         void revNoDup() {
                 //Creating java stack class
                Stack<Character> stack = new Stack<>(); 
                for(int i=0;i<word.length();i++) {
                        if(i==0) {
                                //Appending first character of word
                                stack.push(word.charAt(i));
                        }
                        else {
                                //Validating next character with previous character
                                if(Character.toLowerCase(stack.peek())!=Character.toLowerCase(word.charAt(i))) {
                                        stack.push(word.charAt(i));
                                }
                        }
                }
                // Creating an iterator 
        Iterator value = stack.iterator(); 
        String name="";
        // Displaying the characters 
        // after iterating through the stack 
        //Adding each character to name variable
        while (value.hasNext()) { 
            name = name+value.next(); 
        } 
        //Printing name variable in reverse
        for(int i=name.length()-1;i>=0;i--)
                System.out.print(name.charAt(i));
        }
}

Sample Input and Output:

Enter a word: Tomorrow
woromoT

Enter a word: LiriLl
LiriL

//Please leave comment, if you have any doubts. THANK YOU.