/*
 * Simple example of recursion -- factorial.
 */
#include <stdio.h>

int factorial(int n);

int main(void) {
	int n;
	printf("enter integer value\n");
	if (scanf("%d", &n) == 1) {
		printf("factorial of %d is %d\n", n, factorial(n));
		return 0;
	}
	else {
		printf("not an integer value\n");
		return 1;
	}
}

int factorial(int n) {
	if (n <= 0) 
		return 1;
	else 
		return n*factorial(n-1);
}