Fibonacci Series in C++ Fibonacci Series in C++: In case of fibonacci series, next number is the sum of previous two numbers for example 0, 1, 1, 2, 3, 5, 8, 13, 21 etc. The first two numbers of fibonacci series are 0 and 1. There are two ways to write the fibonacci series program: Fibonacci Series without recursion Fibonacci Series using recursion

Fibonaccci Series in C++ without Recursion

Let's see the fibonacci series program in C++ without recursion.

#include <iostream>

using namespace std;
int main()
{
    int f0 = 0,f1 = 1,f,i, num;
    cout<<"Enter the number of elements: ";
    cin>>num;
    cout<<f0<<" "<<f1<<" "; //printing 0 and 1 
    for(i=2;i<num;i++)//loop starts from 2 because 0 and 1 are already printed
    {
        f=f0+f1;
        cout<<" "<< f;
        f0 = f1;
        f1 = f;
    }
    return 0;
}

Output:

Enter the number of elements: 8

1  1 2 3 5 8 13 21 

Fibonnaci series using recursion in C++

Let's see the fibonacci series program in C++ using recursion.

#include<iostream>    

using namespace std;      

void printFibonacci(int n){    

    static int n1=0, n2=1, n3;    

    if(n>0){    

         n3 = n1 + n2;    

         n1 = n2;    

         n2 = n3;    

 cout<<n3<<" ";    

         printFibonacci(n-1);    

    }    

}    

int main(){    

    int n;    

    cout<<"Enter the number of elements: ";    

    cin>>n;    

    cout<<"Fibonacci Series: ";    

    cout<<"0 "<<"1 ";  

    printFibonacci(n-2);  //n-2 because 2 numbers are already printed    

     return 0;  

}

Output:

Enter the number of elements: 12 

 Fibonacci Series: 0 1 1 2 3 5 8 13 21 34 55 89 

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