Disarium Number Program in Java with Examples

In this post I will be sharing what is Disarium number, examples of Disarium number , algorithm and program in java to check whether a given number is Disarium or not.

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What is Disarium Number

Disarium number can be defined as a number whose sum of digits, powered with their respective position, is equal to the original number.

Examples:

Below are examples of numbers which are Disarium

Number to check : 89 

81+92 = 8 + 81 = 89           // 89 is a Disarium Number

Number to check : 135 

11+32+53 = 1 + 9 + 125 = 135  //135 is a Disarium Number

Number to check : 175 

11+72+53 = 1 + 49 + 125 = 175 //175 is a Disarium Number

Number to check : 518 

51+12+83= 5 + 1 + 512 = 518   //518 is a Disarium Number

Below are examples of numbers which are NOT Disarium

Number to check : 19 

11+92 = 1 + 81 = 82           // 19 is not a Disarium Number
 

Number to check : 134 

11+32+43 = 1 + 9 + 64 = 74    //134 is not a Disarium Number

Number to check : 176 

11+72+63 = 1 + 49 + 216 = 266 //176 is not a Disarium Number

Number to check : 512  

51+12+23= 5 + 1 + 8 = 14      //512 is not a Disarium Number

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Java Program for Disarium Number

import java.util.*;

public class JavaHungry {
    public static void main(String args[]) {

        System.out.println("Input number : ");
        Scanner scan = new Scanner(System.in);
        int inputNumber = scan.nextInt();
        Boolean result = checkDisarium(inputNumber);
        if (result == true)
            System.out.print(inputNumber + " is a Disarium number");
        else    
            System.out.print(inputNumber + " is not a Disarium number");
    }
    
    public static boolean checkDisarium(int inputNumber) {

        //Calculate number of digits in the inputNumber
        int numOfDigits = Integer.toString(inputNumber).length();
        
        // Initialize sumOfDigits of inputNumber
        int sumOfDigits = 0;
        
        // Create a copy of the inputNumber 
        int num = inputNumber;
        
        /* Calculate the sum of digits powered
        with their respective position */
        while (num != 0) {
          // Get the rightmost digit 
          int currentDigit = num % 10;
          sumOfDigits = (int) (sumOfDigits + Math.pow(currentDigit, numOfDigits));
          numOfDigits--;
          num = num / 10;
        }
        /* If sumOfDigits is same as inputNumber then 
        the number is Disarium, otherwise not */ 
        return (sumOfDigits == inputNumber);
    }
}

Output :
Input number : 135
135 is a Disarium number 

Algorithm for Disarium Number

1. Calculate number of digits present in the inputNumber(original number) by using length() method.

2. Initialize sumOfDigits variable to 0 as it will represent the sum of the digits powered with their respective position.

3. Create a copy of inputNumber (original number) by storing its value in variable num.

4. Using while loop

     a. Get the rightmost digit of variable num by using (num % 10). Store its value in variable    currentDigit.
     b. Use Math.pow() function and calculate the value of currentDigit raised to power its position.
     c. add the value of Math.pow() function to sumOfDigits variable. 

5. Check whether the variable sumOfDigits is equal to inputNumber (original number).

     a. If both are equal then the inputNumber is Disarium.
     b. Otherwise, the inputNumber is not a Disarium number.

That's all for the day , please mention in comments if you know any other way to implement Disarium number program in java.