Java Program to Print Armstrong Numbers

What is an Armstrong Number?

A Number is Armstrong, if the sum of the cubes of the digits of number is equal to the number itself.

Example:

153=(1*1*1) + (5*5*5) + (3*3*3) =153

1, 153, 370, 371, 407 are possible Armstrong numbers under 1000.

Java Code to find Armstrong numbers ranging between 1 to n.

import java.util.Scanner;
public class Armstrong
{
    static boolean armstrong(int n)
    {
        int sum = 0;
        int r;
        int num = n;
        while (n!=0)
        {
            r = n%10;
            sum = sum+(r*r*r);
            n = n/10;
        }
        if(sum == num)
            return true;
        else
            return false;
    }
    public static void main(String[] args)
    {
        Scanner obj = new Scanner(System.in);
        System.out.println("enter the value for n");
        int n = obj.nextInt();
        for(int i=1; i<=n; i++)
        {
            if(armstrong(i))
                System.out.println(i);
        }
    }


}

Output:

>enter the value for n
500
1
153
370
371
407