LinuxConfig -

Here is a small program to clalculate Fibonacci numbers using c++ language. No tampering with the code needed ( only iprovements ! ) just copy and compile with g++ FibonacciNumber.cpp -o FibonacciNumber and run ./FibonacciNumber

#include <iostream>
#include <cstdlib>

void HowMany(int *numbers);
void CalculateFibonacci(int *numbers);

int main() {

int numbers = 0;

HowMany(&numbers);
CalculateFibonacci(&numbers);

return 0;
}


void HowMany(int *numbers)

{
   // use pointers as parameter, not references
   std::cout << "How many Fibonacci numbers would you like to calculate? ";
   std::cin >> *numbers;
   if ((!std::cin.good()) || ( *numbers <= 1 ||  ( *numbers >= 48 )))

   {
      printf("Invalid number entered ! I calculate only more than 0 or less then 48 Fibonacci numbers !! \n");
      exit(1);
   }

}

void CalculateFibonacci(int *numbers) 
{
	int i = 0;

	unsigned long a = 1;
	unsigned long b = 0;

	unsigned long fibonacci_number = 0;

	while(i < *numbers) {
		b= fibonacci_number;

		fibonacci_number = a + b;
		std::cout << "Fibonacci number: " << i+1 << ". " << fibonacci_number << "\n";

		a = b;
		i++;
	}
	std::cout << std::endl;
}

OUTPUT:

./FibonacciNumber
How many Fibonacci numbers would you like to calculate? 30
Fibonacci number: 1. 1
Fibonacci number: 2. 1
Fibonacci number: 3. 2
Fibonacci number: 4. 3
Fibonacci number: 5. 5
Fibonacci number: 6. 8
Fibonacci number: 7. 13
Fibonacci number: 8. 21
Fibonacci number: 9. 34
Fibonacci number: 10. 55
Fibonacci number: 11. 89
Fibonacci number: 12. 144
Fibonacci number: 13. 233
Fibonacci number: 14. 377
Fibonacci number: 15. 610
Fibonacci number: 16. 987
Fibonacci number: 17. 1597
Fibonacci number: 18. 2584
Fibonacci number: 19. 4181
Fibonacci number: 20. 6765
Fibonacci number: 21. 10946
Fibonacci number: 22. 17711
Fibonacci number: 23. 28657
Fibonacci number: 24. 46368
Fibonacci number: 25. 75025
Fibonacci number: 26. 121393
Fibonacci number: 27. 196418
Fibonacci number: 28. 317811
Fibonacci number: 29. 514229
Fibonacci number: 30. 832040