/*
 * Program to Check Prime or Armstrong Number 
 * It does this same as armstrng.c, but uses long data types to be able check Numbers over 65536 
 */
	
#include <stdio.h>

	int checkPrimeNumber(unsigned long);
	int checkArmstrongNumber(unsigned long);
	unsigned long pow(int, int);
	
/* Entry point to program */
int main() 
{
	unsigned long num;
	int flag;
	printf("Enter a positive integer: ");
	scanf("%ld", &num);

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

	/* Check Armstrong number */
	flag = checkArmstrongNumber(num);
	if (flag == 1)
		printf("%ld is an Armstrong number.", num);
	else
		printf("%ld is not an Armstrong number.", num);
	return 0;
}

/* Function check Armstrong number */
int checkPrimeNumber(unsigned long num) 
{
	unsigned long i; 
	int 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(unsigned long num) 
{
	unsigned long original, rem, result = 0;
	int 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 */
unsigned long pow(int base, int exponent)
{
	unsigned long pow = 1;
	for (exponent; exponent > 0; exponent--)
	{
		pow = pow * base;
	}

	return pow;
}