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 <stdio.h>
int main() {
	int num=153, new_num, rem, res = 0;
	new_num = num;
	while (new_num != 0) {
		rem = new_num % 10;
		res += rem * rem * rem;
		new_num /= 10;
	}
	if (res == num)
		printf("The number %d is an Armstrong number.", num);
	else
		printf("The number %d is not an Armstrong number.", num);
	return 0;
}

Output

The number 153 is an Armstrong number.