Print a string of fibonacci recursively in C#

Question

Can that be done with no while loops?

static void Main(string[] args)
{
    Console.WriteLine(\"Please enter a number\");
    int number = Convert.ToInt32(C         


        

Answer 1

That's a way to do it by returning a value into the main.

public static void Main() {

    Console.WriteLine("Introduce the number");
    int num = Convert.ToInt32(Console.ReadLine());

    int num1 = 1, num2 = 1, counter = num-2; 

//Take 2 out to match the list as first 2 numbers doesn't count in the function.

    Console.WriteLine(Fibo(num1, num2, counter));
}

public static int Fibo(int num1, int num2, int counter)    {

    int temp = num1;

    if (counter <= 0)
        return num2;
    else
        return Fibo(num1 = num2, num2 += temp, counter-1);
}

Answer 2

I realize this may be an old thread, but oh well I think this kinda question is good in its nature.

Using while loop/or recursive way of doing is not the optimal way of doing as it takes a O(2^n) times. A better way to do this is using what is already in memory like below. This should take at most O(n) time.

Cheers!

 static double fibDynamic(int n)
        {
            double[] array = new double[n];
            array[0] = array[1] = 1;

            for(int i = 2; i < n; i++)
            {
                array[i] = array[i - 1] + array[i - 2];
            }
            return array[n-1];
        }

Answer 3

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static int Main(string[] args)
        {

            int n, i = 0, c;
            Console.WriteLine("Enter the number of terms:");
            n = Convert.ToInt16(Console.ReadLine());

            Console.WriteLine("Fibonacci series\n");

            for (c = 1; c <= n; c++)
            {
                int result = FibonacciFunction(i);
                Console.Write(result + " " );
                i++;
            }
            Console.WriteLine();
            return 0;
        }

        public static int FibonacciFunction(int n)
        {
            if (n == 0)
            {
                return 0;
            }
            else if (n == 1)
            {
                return 1;
            }
            else
            {
                return (FibonacciFunction(n - 1) + FibonacciFunction(n - 2));
            }
        }

    }
}

Answer 4

public static int Fibonatchi(int position) {

    if(position == 0) {
        return 1;
    }
    if(position == 1) {
        return 1;
    } else {
        return Fibonatchi(position - 2) + Fibonatchi(position - 1);
    }
}

Answer 5

namespace Algorithms
{
    class Program
    {
        static void Main(string[] args)
        {
            string fibResult = "";
            fibResult =  FibCal(10);
            Console.WriteLine(fibResult);
            Console.ReadLine();
        }

        public static string FibCal(int n)
        {
            string series = "";
            int k, f1, f2 , f = 0;
            f1 = f2 = 1;
            if (n < 2) 
                return n.ToString();
            else
                for (k = 0; k < n; k++)
                {
                    f = f1 + f2;
                    f2 = f1;
                    f1 = f;
                    series += f.ToString() + ",";
                }

            return series;
        }

    }
}

Hope this helps