using System;

using System.Linq;

using System.Collections.Generic;

​

public static class ArithmeticProgression

{

    public static List<int> GetTerms(int start, int step, int term_count){

        var terms = new List<int>();

        var next_term = start;

​

        do

        {

            terms.Add(next_term);

            next_term += step;

​

        } while (terms.Count() < term_count);

​

        return terms;

    }

}   

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Arithmetic Progression in C#\n");

        RunDemo();

        RunDemo(2, 3, 6);       

        RunDemo(1, 4, 5);

        RunDemo(13, 7, 15, false);

        RunDemo(133, 74, 45, false);

    }

    public static void RunDemo(int start=1, int step=1, int term_count=10, bool showEachTerm = true)

    {

        var terms = ArithmeticProgression.GetTerms(start, step, term_count);

​

        var mainSectionStart = "".PadRight(33, '=');

        var mainSection = "".PadRight(33, '-');

        var subSection = "".PadRight(20, '-');

        var subSectionEnd = "".PadRight(20, '=');

​

        Console.WriteLine(

            $"{mainSectionStart}\n" +

            $"- Arithmetic Progression Options:\n" +

            $"{mainSection}\n" +

            $"- Start at:\t\t{start}\n" +

            $"- Increase by:\t\t{step}\n" +

            $"- Number of Terms:\t{term_count}\n" +

            $"- ShowEachTerm:\t{showEachTerm}\n" +

            $"{subSection}\n" +

            $"- Sum of Terms:\t{terms.Sum()}");

        if (showEachTerm)

        {           

            Console.WriteLine(

                $"{subSection}\n" +

                $"- List of Terms:\n{subSection}");

            terms.ForEach(term => Console.WriteLine($"  {term}"));

        }

​

        Console.WriteLine($"{subSectionEnd}\n\n");

    }

​

}