using System;

using System.Collections.Generic;

using System.Linq;

//using System.Text;

//using System.Threading.Tasks;

public class Program

{

    public static void Main()

    {

        //Get a list of fibonacci numbers

        //  1st param - SequenceType: can be even, odd, all

        //  2nd param - Stops the sequence when the sum of the values reaches this integer

        List<int> result = CFibonacci.CalculateFibonacciSequence(

            CFibonacci.SequenceType.even, 

            4000000

        );

​

        foreach (var item in result)

        {

            Console.WriteLine(item.ToString());

        }

        Console.WriteLine(String.Format("Sum of fibonacci numbers {0}",result.Sum().ToString()));

    }

}

​

  class CFibonacci

    {

    public enum SequenceType { odd, even, all };

    CFibonacci()

        {

            //Initialise class. SImple class so don't need this to do anything

        }

​

​

    public static List<int> CalculateFibonacciSequence(SequenceType st, int EndValueCount)

    {

        List<int> CalculatedNumbers = new() { 1, 2 };

        int i = 0;

​

        while (CalculatedNumbers[i + 1] <= EndValueCount)

        {

            CalculatedNumbers.Add(CalculatedNumbers[i] + CalculatedNumbers[i + 1]);

            i++;

        }

        switch(st)

        {

            case SequenceType.odd:  CalculatedNumbers.RemoveAll(i => i % 2 == 0); break;

            case SequenceType.even: CalculatedNumbers.RemoveAll(i => i % 2 != 0); break;

        }

        return CalculatedNumbers;

    }

​

​

}