Question

Java programming write a program to input a number and display whether it is a disarium number or not .and a disarium number is a number in which the sum of the digits to the power of their respective position is equal to the number itself .example 135 is equal to 11 + 32 + 53

Answer 1

/* Copy the Code into an IDE.
 * Description and Explanation are given as comments
 * Some Screenshots are attached
 */



import java.util.Scanner;           //Importing Scanner
public class Disarium_Number        //Creating Class    
{
    public static void main(String[] args)      //Creating main() function
    {
        Scanner sc = new Scanner(System.in);    //Creating Scanner Object

        System.out.println("A Disarium Number is a number in which the sum of the digits to the power of their respective position is equal to the number itself\n");
        
        System.out.print("Enter a number: ");   //Asking for User Input
        String num = sc.next();         //Scanning User Input as a String, stored in num

        try             //try-catch blocks are used for handling Exceptions
        {
            int sum=0;      //sum will contain the Sum of digits raised to respective powers

            for(int i=0;i<num.length();i++)     //Loop variable i will go through each character of String num
            {
                char ch = num.charAt(i);        //Extracting character from num into ch
                int digit = Integer.parseInt(Character.toString(ch));   //Converting ch into integer

                int newdigit = (int)Math.pow(digit,i+1);    //Raising each digit to respective power

                sum = sum + newdigit;           //Adding newdigit to sum

            }

            String newnum = Integer.toString(sum);      //Converting sum into a String

            if(num.equals(newnum))          //Comparing num and newnum
            {
                System.out.println(num+" is a Disarium Number.");
            }
            else
            {
                System.out.println(num+" is not a Disarium Number.");
            }
        }
        catch(Exception e)      //Usually, NumberFormatException can arise if input is not a number. But general case used.
        {
            System.out.println("Invalid Input");
            System.out.println(e);
        }
    }
}

Answer 2

The answers which I saw above looked a little complicated. The one which I am posting might seem a little easy for beginners as well as pros also....

import java.util.*;

class disarium

{public static void main()

{Scanner sn = new Scanner(System.in);

int n, n1, d=0, s=0, c=0;

System.out.println("Enter a number");

n = sn.nextInt();

n1 = n;

while(n>0)

{n = n/10;

c++;

}

while(n>0)

{d = n%10;

s = s+(int)(Math.pow(d,c));

n = n/10;

c--;

}

if(s==n1)

System.out.println(n1+" is a disarium number");

else

System.out.println(n1+" is not a disarium number");

}

}