Question

: This exercise will give you a review of Strings and String processing. Create a class called MyString that has one String called word as its attribute and the following methods: Constructor that accepts a String argument and sets the attribute. Method permute that returns a permuted version of word. For this method, exchange random pairs of letters in the String. To get a good permutation, if the length of the String is n, then perform 2n swaps. Use this in an application called Jumble that prompts the user for a word and the required number of jumbled versions and prints the jumbled words. For example, Enter the word: mixed Enter the number of jumbled versions required: 10 xdmei eidmx miexd emdxi idexm demix xdemi ixdme eximd xemdi xdeim Notes: 1. It is tricky to swap two characters in a String. One way to accomplish this is to convert your String into an array of characters, swapping the characters in the array, converting it back to a String and returning it. char[] chars = word.toCharArray(); will convert a String word to a char array chars. String result = new String(chars); converts a char array chars into a String. p 6 2. Use Math.random to generate random numbers. (int)(n*Math.random()) generates a random number between 0 and n-1. java

Answer 1

JAVA CODE: (MyString.java)

import java.util.*;

public class MyString
{
   //variable to store the word
   String word;  
  
  
   // constructor to initialize the object
   public MyString(String word)
   {
       this.word=word;
   }
  
   // method to return a permuted word
   public String permute()
   {
  
       // converting word into character array
       char[] chars = word.toCharArray();
      
      
       // finding the length of the word
       int n=word.length();
      
      
       // swapping characters for 2 * n times
       for(int i=0;i< 2*n;i++)
       {
          
           // finding two random numbers
           int r1=(int)(n*Math.random());
           int r2=(int)(n*Math.random());
          
           //swapping the characters at position r1 and r2 of the array
           char t=chars[r1];          
           chars[r1]=chars[r2];
           chars[r2]=t;          
       }
      
       //converting character array into string
       String result = new String(chars);
      
       // return the string
       return result;
   }
}

JAVA CODE (Jumble.java)

import java.util.*;

public class Jumble
{
   public static void main(String args[])
   {
       //creating scanner object to get keyboard input
       Scanner kb=new Scanner(System.in);
      
       //getting the word from the user
       System.out.print("Enter the word: ");
       String word=kb.next();
      
       // getting the n value
       System.out.print("\nEnter the number of jumbled versions required: ");
       int n=kb.nextInt();
      
       System.out.println();
      
       // calling the permute() method for n times
       for(int i=0;i<n;i++)
       {
           MyString ob=new MyString(word);
           System.out.println(ob.permute());
       }
      
   }
  
}

SCREENSHOT FOR OUTPUT: