/*
 * Program to Check Prime or Armstrong Number 
 */

#include <stdio.h>
	
	int checkPrimeNumber(int);
	int checkArmstrongNumber(int);
	int pow(int, int);
	
/* Entry point to program */
int main() 
{
	int num, flag;
	printf("Enter a positive integer: ");
	scanf("%d", &num);

	/* Check prime number */
	flag = checkPrimeNumber(num);
	if (flag == 1)
		printf("%d is a prime number.\n", num);
	else
		printf("%d is not a prime number.\n", num);

	/* Check Armstrong number */
	flag = checkArmstrongNumber(num);
	if (flag == 1)
		printf("%d is an Armstrong number.", num);
	else
		printf("%d is not an Armstrong number.", num);

	return 0;
}

/* Function check prime number */
int checkPrimeNumber(int num) 
{
	int i, flag = 1;
	for (i = 2; i <= num / 2; ++i) 
	{
		/* Condition for non-prime number */
		if (num % i == 0) 
		{
			flag = 0;
			break;
		}
	}
	
	return flag;
}

/* Function check Armstrong number */
int checkArmstrongNumber(int num) 
{
	int original, rem, result = 0, n = 0, flag;

	original = num;
	while (original != 0)
	{
		original /= 10;
		++n;
	}

	original = num;
	while (original != 0) 
	{
		rem = original % 10;
		result += pow(rem, n);
		original /= 10;
	}

	/* Condition for Armstrong number */
	if (result == num)
		flag = 1;
	else
		flag = 0;
		
	return flag;
}

/* Function computes the power of a number */
int pow(int base, int exponent)
{
	int pow = 1;
	for (exponent; exponent > 0; exponent--)
	{
		pow = pow * base;
	}

	return pow;
}