Fibonacci Number
  Note:
  
      
      
    This code was written during a crunch period and isn't perfect. There will
    be some errant spacing, some files will be
    using namespace std, etc. But it's all still usable and can be a
    handy guideline if you're learning Data Structures.
  
int fib(int n)
{
    if (n == 0)
    {
        return 0;
    }
    else if (n == 1)
    {
        return 1;
    }
    return fib(n - 1) + fib(n - 2);
}
int main()
{
    std::cout << fib(5) << '\n';
    std::cout << fib(8) << '\n';
    std::cout << fib(9) << '\n';
}