C# Fundamentals - 03. ConcatList - MidExam 30.06.2020 Group 1

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;

namespace _30._06._2019_Mid_Exam_Group_1
{
    class ContactList
    {
        static void Main(string[] args)
        {
            List<string> contactList = Console.ReadLine()
                                       .Split(' ')
                                       .ToList();

            while (true)
            {
                string[] instructions = Console.ReadLine().Split(' ').ToArray();
                string command = instructions[0];

                if (command == "Add")
                {
                    string contact = instructions[1];
                    int index = int.Parse(instructions[2]);

                    if (!contactList.Contains(contact))
                    {
                        contactList.Add(contact);
                    }
                    else
                    {
                        if (0 <= index && index <= contactList.Count - 1)
                        {
                            contactList.Insert(index, contact);
                        }
                    }
                }
                else if (command == "Remove")
                {
                    int index = int.Parse(instructions[1]);
                    if (0 <= index && index <= contactList.Count - 1)
                    {
                        contactList.RemoveAt(index);
                    }
                }
                else if (command == "Export")
                {
                    int startIndex = int.Parse(instructions[1]);
                    int count = int.Parse(instructions[2]);

                    if (0 <= startIndex && startIndex <= contactList.Count - 1)
                    {
                        if (count > contactList.Count - 1)
                        {
                            for (int i = startIndex; i < contactList.Count; i++)
                            {
                                Console.Write($"{contactList[i]} ");
                            }
                            Console.WriteLine();
                        }
                        else
                        {
                            for (int i = startIndex; i < startIndex + count; i++)
                            {
                                Console.Write($"{contactList[i]} ");
                            }
                            Console.WriteLine();
                        }
                    }
                }
                else if (command == "Print")
                {
                    string howToPrint = instructions[1];
                    if (howToPrint == "Normal")
                    {
                        Console.Write("Contacts: ");
                        Console.WriteLine(string.Join(' ', contactList));
                    }
                    else
                    {
                        contactList.Reverse();
                        Console.Write("Contacts: ");
                        Console.WriteLine(string.Join(' ', contactList));
                    }
                    break;
                }
            }
        }
    }
}