factorial

#include <stdio.h>

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

int main(void){
    int n, f;
    printf("Factorial(N)\n");

    while(1){
        printf("\nN = ");
        scanf("%d", &n);

        if(n >= 0){
            f = factorial(n);
            printf("Factorial(%d) = %d\n", n, f);
        }
        else{
             printf("factorial is not defined for negative numbers");
        }
    }
}