Q. Java program to check whether the given number N is Armstrong number or not.


Here you will find an algorithm and program in Java programming language to check whether the given number N is Armstrong number or not. First let us understand what is Armstrong number

Explanation : A Armstrong Number is a number that is equal to sum of cubes of each digits.

For Example : 153. So as we can see that the sum of cubes of each digit (1^3=1, 5^3=125, 3^3=27 => 1+125+27=153) is equal to it's number. So 153 is an Armstrong number.

Armstrong Number Algorithm


START
  step 1 : read number
  step 2 : set sum=0 and duplicate=number
  step 3 : reminder=number%10
  step 4 : sum=sum+(reminder*reminder*reminder)
  step 5 : number=number/10
  step 6 : repeat steps 4 to 6 until number > 0
  step 7 : if sum = duplicate
  step 8 : display number is armstrong
  step 9 : else 
  step 10 : display number is not armstrong
STOP

Java Program To Check Armstrong Number

public class LFC {
  public static void main(String[] args) {
    int num = 153, new_num, rem, res = 0;
    new_num = num;
    while (new_num != 0)
    {
      rem = new_num % 10;
      res += Math.pow(rem, 3);
      new_num /= 10;
    }
    if(res == num)
      System.out.println("The number "+num+" is an Armstrong number.");
    else
      System.out.println("The number "+num+" is not an Armstrong number.");
  }
}

Output

The number 153 is an Armstrong number.