Factorial C

#include <stdio.h>

int factor_pointer(int *n);
int factor_recursive(int n);

int main(void) {
  int *num;
  int factorial = 0;

  printf("Enter a number to factorial:");
  scanf("%d", num);
  factorial  = factor_recursive(*num);
  printf("%d", factorial);
  return 0;
}
//
int factor_pointer(int *n)
{
  int ans =1;
  for(int i =1; i<=*n; i++)
  {
    ans *= i;
  }
  return ans;
}
int factor_recursive(int n)
{
  if(n == 1)
  {
    return 1;
  }
  return n*factor_recursive(n-1);
}