3.1

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

namespace CSLight3
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] numbersOfTable = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
            int[] countPlaceOnTable = { 1, 5, 2, 3, 6, 7, 8, 1, 5, 2 };
            int[] reservedTableArray = new int[0];
            int countOfReservedTable = 0;
            int countOfGuest;
            int reservedTable;
            int indexOfReservedTable = -1;
            bool checkReservedTable = false;

            while (true)
            {
                Console.WriteLine("Система бронирования столов");
                int maxCountGuest = int.MinValue;
                for (int i = 0; i < countPlaceOnTable.Length; i++)
                {
                    if (maxCountGuest <= countPlaceOnTable[i])
                    {
                        maxCountGuest = countPlaceOnTable[i];
                    }
                }
                Console.WriteLine("Сколько гостей будет?");
                countOfGuest = Convert.ToInt32(Console.ReadLine());

                if (numbersOfTable.Length == 0)
                {
                    Console.WriteLine("Больше свободных столов нет");
                }
                else if (countOfGuest > maxCountGuest)
                {
                    Console.WriteLine("Такое количество гостей " +
                        "не сможет поместиться за один стол");
                }
                else
                {
                    for (int i = 0; i < countPlaceOnTable.Length; i++)
                    {
                        if (countPlaceOnTable[i] >= countOfGuest)
                        {
                            Console.WriteLine("Стол № " + numbersOfTable[i]
                                + " имеет " + countPlaceOnTable[i]
                                + " свободных мест");
                        }
                    }
                    Console.WriteLine();

                    if (countOfReservedTable != 0)
                    {
                        for (int i = 0; i < reservedTableArray.Length; i++)
                        {
                            Console.WriteLine("Стол № " + reservedTableArray[i] +
                                " зарезервирован");
                        }
                    }
                    else
                    {
                        Console.WriteLine("\nНи один стол не забронирован");
                    }

                    Console.WriteLine("\nКакой стол вы хотите забронировать?");
                    reservedTable = Convert.ToInt32(Console.ReadLine());

                    if (reservedTable < 0)
                    {
                        Console.WriteLine("Ошибка ввода");

                    }
                    else
                    {
                        int[] newReservedTable = new int[reservedTableArray.Length + 1];
                        for (int i = 0; i < reservedTableArray.Length; i++)
                        {

                            newReservedTable[i] = reservedTableArray[i];
                        }

                        for (int i = 0; i < reservedTableArray.Length; i++)
                        {
                            if (reservedTable == reservedTableArray[i])
                            {
                                checkReservedTable = true;
                                break;
                            }
                        }
                        if (!checkReservedTable)
                        {
                            newReservedTable[countOfReservedTable] = reservedTable;
                            reservedTableArray = newReservedTable;
                            countOfReservedTable++;

                            for (int i = 0; i < numbersOfTable.Length; i++)
                            {
                                if (numbersOfTable[i] == reservedTable)
                                {
                                    indexOfReservedTable = i;
                                }
                            }

                            if (indexOfReservedTable != -1)
                            {
                                int[] newNumberOfTable = new int[numbersOfTable.Length - 1];
                                int counterOfNumbersArray = 0;
                                for (int i = 0; i < numbersOfTable.Length; i++)
                                {
                                    if (i == indexOfReservedTable) continue;
                                    newNumberOfTable[counterOfNumbersArray] = numbersOfTable[i];
                                    counterOfNumbersArray++;
                                }
                                numbersOfTable = newNumberOfTable;

                                int[] newCountPlaceOnTable = new int[countPlaceOnTable.Length - 1];
                                int counterOfPlaceArray = 0;
                                for (int i = 0; i < countPlaceOnTable.Length; i++)
                                {
                                    if (i == indexOfReservedTable) continue;
                                    newCountPlaceOnTable[counterOfPlaceArray] = countPlaceOnTable[i];
                                    counterOfPlaceArray++;
                                }
                                countPlaceOnTable = newCountPlaceOnTable;

                                Console.WriteLine("Стол успешно забронирован");
                            }
                            else
                            {
                                Console.WriteLine("Ошибка ввода");
                            }
                        }
                        else
                        {
                            Console.WriteLine("Этот стол уже забронирован");
                            checkReservedTable = false;
                        }
                    }
                }
                Console.WriteLine("\nНажмите любую клавишу...");
                Console.ReadKey();
                Console.Clear();
            }
        }
    }
}