using System;

using System.Collections.Generic;

using System.Linq;

​

class Elevator

{

    public int Id { get; private set; }

    public int CurrentFloor { get; private set; }

​

    public Elevator(int id, int currentFloor = 1)

    {

        Id = id;

        CurrentFloor = currentFloor;

    }

​

    public void MoveToFloor(int floor)

    {

        CurrentFloor = floor;

    }

​

    public int DistanceToFloor(int floor)

    {

        return Math.Abs(CurrentFloor - floor);

    }

​

    public override string ToString()

    {

        return $"Elevator {Id} is now on floor {CurrentFloor}";

    }

}

​

class Building

{

    private List<Elevator> elevators;

​

    public Building(int numElevators = 4, int numFloors = 10)

    {

        elevators = new List<Elevator>();

        for (int i = 0; i < numElevators; i++)

        {

            elevators.Add(new Elevator(i + 1));

        }

    }

​

    public Elevator CallElevator(int floor)

    {

        Elevator closestElevator = elevators.OrderBy(e => e.DistanceToFloor(floor)).First();

        closestElevator.MoveToFloor(floor);

        return closestElevator;

    }

​

    public void DisplayStatus()

    {

        foreach (var elevator in elevators)

        {

            Console.WriteLine(elevator);

        }

    }

}

​

class Program

{

    static void Main(string[] args)

    {

        Building building = new Building();

​

        while (true)

        {

            Console.WriteLine("\nBuilding status:");

            building.DisplayStatus();

​

            Console.Write("\nEnter the floor number to call the elevator (1-10) or 'q' to quit: ");

            string userInput = Console.ReadLine().Trim().ToLower();

​

            if (userInput == "q")

            {

                Console.WriteLine("Exiting...");

                break;

            }

​

            try

            {

                int floor = int.Parse(userInput);

​

                if (floor < 1 || floor > 10)

                {

                    Console.WriteLine("Invalid floor. Please enter a number between 1 and 10.");

                }

                else

                {

                    Elevator selectedElevator = building.CallElevator(floor);

                    Console.WriteLine($"\nElevator {selectedElevator.Id} has been selected and moved to floor {floor}.");

                }

            }

            catch (FormatException)

            {

                Console.WriteLine("Invalid input. Please enter a valid floor number or 'q' to quit.");

            }

            catch (Exception ex)

            {

                Console.WriteLine($"An error occurred: {ex.Message}");

            }

        }

    }

}

​