Factorial

gistfile1.c

#include <stdio.h>

int factorial(int a);

int main(int argc, char** argv)
{
    int x;
    scanf("%d",&x);
    printf("%d", factorial(x));
    return 0;
}

int factorial(int a)
{
    int x = 1;
	while(a > 0)
	{
		x = x*a;
		--a;
	}
	return x;
}