## Sunday, February 2, 2020

### Recursion(Fibonacci series)

Recursion(Fibonacci series)

In this tutorial another example of Recursion. You can see the detailed view of recursion in this post, where we discussed calculating the factorial of a number with recursion. Fibonacci series is a sequence of Fibonacci numbers like,

1,1,2,3,5,8,13,21,34,55,89,144,...

We can define this series in mathematical terms by the following expression,

We can summarise a recursive method to calculate the Fibonacci number for given value n as,

Calculating Fibonacci number is very easy, we can see in the following figure,

Example

public class DemoRecursion {// Calculate Fibonacci by recursion

public static void main(String[] args) {
DemoRecursion d=new DemoRecursion();
//to print series
for(int i=0;i<11;i++)
{
System.out.print(d.fibonacci(i)+"\t");
}
//System.out.println(d.fibonacci(9));
}
int fibonacci(int num)// Fibonacci recursive method
{
if(num==0)
{
return 0;
}
else if(num==1)
{
return 1;
}
else
{
return fibonacci(num-2)+fibonacci(num-1);
}
}
}
//***********************************************/

Output:
0 1 1 2 3 5 8 13 21 34 55

Video Tutorial