[Banksy]

hey, i have to write a recursive function that computes the factorial of a number given the following prototype:

Code:

void factorial (long argument, long *result)

here's what i have written, it compiles, but whenever i run it i get a segmentation fault. i'm pretty sure i'm just not using the pointer properly, any help would be greatly appreciated.

Code:

#include <stdio>

void factorial(long argument, long *result);

int main(){
    long a;
    long *result;

    *result = 1;
    
        printf("Enter a number: ");
        scanf("%l", &a);

    factorial(a, result);

        return 0;
}

void factorial(long argument, long *result){
    if (argument == 1)
        printf("The factorial of %l is: %l", argument,*result);
    else{
        *result = *result * argument;
        factorial(argument-1, result);    
    }
}

i'm pretty new to C so if there are any other obvious flaws feel free to point them out.