A positive integer is called an Armstrong number of order n if

abcd... = an + bn + cn + dn + ...

In case of an Armstrong number of 3 digits, the sum of cubes of each digit is equal to the number itself. For example:

153 = 1*1*1 + 5*5*5 + 3*3*3  // 153 is an Armstrong number.

This program is built on the concept of how to check whether an integer is an Armstrong number or not.

Example: Armstrong Numbers Between Two Integers

public class Armstrong {

    public static void main(String[] args) {

        int low = 999, high = 99999;

        for(int number = low + 1; number < high; ++number) {
            int digits = 0;
            int result = 0;
            int originalNumber = number;

            // number of digits calculation
            while (originalNumber != 0) {
                originalNumber /= 10;
                ++digits;
            }

            originalNumber = number;

            // result contains sum of nth power of its digits
            while (originalNumber != 0) {
                int remainder = originalNumber % 10;
                result += Math.pow(remainder, digits);
                originalNumber /= 10;
            }

            if (result == number)
                System.out.print(number + " ");
        }
    }
}

Output

1634 8208 9474 54748 92727 93084 

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