Find Armstrong Numbers in a Given Range in java

               Armstrong Number is a number which has a unique feature in it. When you take cube of each digit and sum it, it gives the same number.

Eg:

153 = 1³ +5³ +3³ = 1+125+27 = 153.

Java implementation of finding Armstrong Number in the given range:

• It starts with including the built-in header file.
• Create a class with two functions  itArmstrong() and findArmstrongNos().
• itArmstrong() – it splits each digit separately and raise the power to 3 .
• ‘findArmstrongNos()’ – it finds the Armstrong number in the given range.
• ‘main()’ – reads the input from the user to starting and ending of the range.
• It calls the ‘findArmstrongNos()’ function.

Program:

import java.util.Scanner;

public class ArmstrongNoInRangeEg {

       public static boolean itArmstrong(int n) {

        int originalNo = n, sum = 0, digit = 0;

        // Code to count the number of digits

        int temp = n;

        while (temp > 0) {

            digit++;

            temp /= 10;

        }

        // To find the sum of digits raised to the power of digits

        temp = originalNo;

        while (temp > 0) {

            int digi = temp % 10;

            sum += Math.pow(digi, digit);

            temp /= 10;

        }

        return sum == originalNo;

    }

     // Let us find Armstrong numbers in a given range

    public static void findArmstrongNos(int s, int e) {

        System.out.println("Armstrong Numbers between " + s + " and " + e + ":");

        for (int no = s; no <= e; no++) {

            if (itArmstrong(no)) {

                System.out.print(no + " ");

            }

        }

        System.out.println();

    }

    public static void main(String[] args) {

        Scanner s1 = new Scanner(System.in);

        // Input statements

        System.out.print("Enter the start of range: ");

        int st = s1.nextInt();

        System.out.print("Enter the end of range: ");

        int en = s1.nextInt();

        findArmstrongNos(st, en);

        s1.close();

    }

}

Output:

C:\raji\blog>javac ArmstrongNoInRangeEg.java

C:\raji\blog>java ArmstrongNoInRangeEg

Enter the start of range: 123

Enter the end of range: 1045

Armstrong Numbers between 123 and 1045:

153 370 371 407

That’s it. The java program to find Armstrong number in the given range is done. Hope, this code is easily understandable to you. Keep Coding!!!