Thread: Fibbonacci Code

Hey all, Programming newbie here.

I'm programming the Fibbonacci code, but I can't figure out how to set the condition

"if NOT EQUAL to any numerical value"

This is what I have so far:

Code:

#include <stdio.h>
#include <conio.h>

long fib(int);

int main()
{
  int n;

  printf("Enter the Fibbonacci number you would like to view: ");
  scanf("%i", &n);

  if (WHAT GOES HERE?)
  {
    printf("Input error.\n");
    getch();
  }
  else if (n<0) {
    printf("Fibonacci is undefined for negative integers.\n");
    getch();
  }
  else {
    printf("The %i-th Fibonacci number is %ld\n", n, fib(n));
  }
  getch();
  return 0;
}

long fib(int n)
{
  if (n == 1 || n == 2) 
  {
    return 1;
  } 
  else 
  {
    return (fib(n-1) + fib(n-2));
  }
}

Thanks for the help in advance!