In this artcile you will learn how calculate Fibonacci sequence with using C++ function. The Fibonacci sequence starts with 0 and 1 where the the following number is always a sum of the two preceding numbers. For example, 0,1,1,2,3,5,8 and so on.

**In this tutorial you will learn:**

- How to compile Fibonacci C++ program
- How to run Fibonacci C++ program

## Software Requirements and Conventions Used

Category | Requirements, Conventions or Software Version Used |
---|---|

System | Any Linux distro |

Software | g++ compiler |

Other | Privileged access to your Linux system as root or via the `sudo` command. |

Conventions |
# – requires given linux commands to be executed with root privileges either directly as a root user or by use of `sudo` command$ – requires given linux commands to be executed as a regular non-privileged user |

## How to calculate Fibonacci number sequence step by step instructions

- Install
`g++`

compiler. The procedure is simple as follows:UBUNTU/DEBIAN# apt install g++

RHEL/CENTOS

# dnf groupinstall "Development Tools"

Once ready, confirm the

`g++`

compiler availability on your system:$ g++ --version g++ (Debian 8.3.0-6) 8.3.0

- Use your favourite text editor and save the below C++ code into a file called
`FibonacciNumber.cpp`

:#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 ! Enter number greater than 0 or less than < 48 \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; }

- Compile the above C++ program into a
`FibonacciNumber`

executable binary. To do so run the following`g++`

command from the directory where your`FibonacciNumber.cpp`

source code is located:$ g++ FibonacciNumber.cpp -o FibonacciNumber

The above should compile without any output and errors. As a result, you now have the

`FibonacciNumber`

available in your directory:$ ls FibonacciNumber FibonacciNumber

- Calculate Fibonacci number sequence using the
`FibonacciNumber`

executable binary compiled in the previous step:$ ./FibonacciNumber How many Fibonacci numbers would you like to calculate? 10 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