Write a C# Program to Print Nth Number in Fibonacci Series Recursive Approach?
What is Fibonacci Series?
Fibonacci series is a sequence of numbers in below order:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34… The next number is found by adding up the two numbers before it.
The formula for calculating these numbers is:
F(n) = F(n-1) + F(n-2)
where:
F(n) is the term number.
F(n-1) is the previous term (n-1).
F(n-2) is the term before that (n-2).
it starts either with 0 or 1.
Different ways to print Fibonacci Series in C#?
In C#, there are several ways to print Fibonacci Series.
- Iterative Approach
- Recursion Approach
Recursive Approach:
namespace ConsoleApplication
{
class Program
{
public static int FibonacciSeries(int n)
{
if (n == 0) return 0; //To return the first Fibonacci number
if (n == 1) return 1; //To return the second Fibonacci number
return FibonacciSeries(n - 1) + FibonacciSeries(n - 2);
}
public static void Main(string[] args)
{
Console.Write("Enter the length of the Fibonacci Series: ");
int length = Convert.ToInt32(Console.ReadLine());
for (int i = 0; i < length; i++)
{
Console.Write("{0} ", FibonacciSeries(i));
}
Console.ReadKey();
}
}
}
Output:
here's a C# program to print the Nth number in the Fibonacci series using a recursive approach:
Enter the length of the Fibonacci Series: 12
0112358 13 21 34 55 89.
using System;
class Program
{
// Recursive function to calculate the Nth Fibonacci number
static int Fibonacci(int n)
{
if (n <= 1)
return n;
return Fibonacci(n - 1) + Fibonacci(n - 2);
}
static void Main(string[] args)
{
int n = 10; // Change this to get different Fibonacci numbers
if (n <= 0)
{
Console.WriteLine("Invalid input. Please enter a positive integer.");
}
else
{
Console.WriteLine($"The {n}th number in the Fibonacci series is: {Fibonacci(n)}");
}
}
}
In this program:
- The
Fibonaccifunction is a recursive function that calculates the Nth Fibonacci number. - In the
Mainmethod, you can change the value ofnto get the Nth Fibonacci number you desire. - The program checks if the input
nis a positive integer and prints the Nth Fibonacci number accordingly.