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

Here you will find an algorithm and program in C++ 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.

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

C++ Program To Check Armstrong Number

#include <iostream>
using namespace std;
int main()
{
  int N=153, num, rem, sum = 0;
  num = N;
  while(num != 0)
  {
    rem = num % 10;
    sum += rem * rem * rem;
    num /= 10;
  }
  if(sum == N)
    cout <<"The number "<< N <<" is an Armstrong number.";
  else
    cout <<"The number "<< N <<" is not an Armstrong number.";
  return 0;
}

Output

The number 153 is an Armstrong number.