Question

Design a class NumDude to check if a given number is a Dudeney number or not. (A Dudency number is a positive integer that is a perfect cube, such that the sum of its digits is equal to the cube root of the number.)

Example 5832 = (5 + 8 + 3 +2)³ = (18)³ = 5832

Some of the members of the class are given below:

Class name	unique
Data member/instance variable:
num	to store a positive integer number
Methods/Member functions:
NumDude()	default constructor to initialise the data member with a legal initial value
void input()	to accept a positive integer number
int sumDigits(int x)	returns the sum of the digits of number 'x' using recursive technique
void isDude()	checks whether the given number is a Dudeney number by invoking the function sumDigits() and displays the result with an appropriate message.

Specify the class NumDude giving details of the constructor ( ), void input( ), intsumDigits(int) and void is Dude(). Define a main() function to create an object and call the functions accordingly to enable the task.

Answer 1

import java.util.Scanner;
public class NumDude
{
intnum;
   public NumDude()
   {
num=0;
   }
public void input()
{
  Scanner in = new Scanner(System.in);
  System.out.print(“Enter the number: “);
  num = in.nextInt();
}
public int sumDigits(int x)
{
  if (x=0)
 return 0;
     else
         return x%10 +sumDigits(x/10);
}
public void isDude()
{
   int sdig=sumDigits(num);
   if ( (sdig*sdig*sdig) = num)
      System.out.println(“Dudency number “);
  else
     System.out println(“Not a Dudency number “);
}
public static void main(String args[]) {
  NumDudeob=new NumDude();
  ob.input();
  ob.isDude();
   }
}