Fibonacci Number Using Recursion

#cpp #java #algorithms #recursion

In Below code we have used recursion to return Fibonacci number and Fibonacci series.
To run the code click here.

Example 1:

Input :-

Output :-

Code in C++ :-

#include <iostream>

using namespace std;
int f(int n){
if(n ==0) return 0;
else if(n ==1 || n == 2) return 1;
else return f(n-2)+ f(n-1);
}
int main() {
  int n;
  cin>>n;
  cout<<n<<"th fibonacci number is "<<f(n)<<"\n";
  /*cout<<"Fibonacci Series till " << n <<"\n";
  for(int i =0 ; i < n ; i++){
      cout<<" "<<f(i);
  }*/
}

Code in Java :-

import java.util.*;
public class MyClass {
    public static int f(int n) {
     if(n == 0) return 0;
     else if(n == 1 || n ==2) return 1;
     else return f(n-2) + f(n-1);   
    }

    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        System.out.println(n+"th Febonacci number is :- " + f(n));
    /*  for(int i=0; i< n ; i++){    //uncomment to print series
            System.out.println(" "+f(i));
        } */
        System.out.println("\n Time complexity O(2^n)");
        sc.close();
    }
}

Example 2:

Input :-

Output :-