using System.Collections.Generic;
using System.Threading.Tasks;
private static List<SalesRecord> salesRecords = new();
public static void Main()
var currentServiceProvider = "AWS";
var accManager = GetAccountManager(currentServiceProvider);
Console.WriteLine("Enter User ID:");
var userId = Console.ReadLine();
Console.WriteLine("Enter Password:");
var password = Console.ReadLine();
if (accManager.Authenticate(userId, password))
Console.WriteLine("Authenticated Successfully");
Console.WriteLine("Authentication Failed");
for (var i = 0; i < 10000; i++)
var item = i < 4000 ? "A" : i < 8000 ? "B" : "C";
salesRecords.Add(new SalesRecord(item));
Parallel.ForEach(salesRecords, salesRecord =>
salesRecord.Qty = new Random().Next(1, 100);
Console.WriteLine("Which item do you want to view? (A/B/C):");
var chosenItem = Console.ReadLine();
var filteredRecords = salesRecords
.Where(record => record.Item == chosenItem)
.OrderByDescending(record => record.Qty);
foreach (var record in filteredRecords)
Console.WriteLine($"Item: {record.Item}, Quantity: {record.Qty}");
public static IAccountManager GetAccountManager(string serviceProvider)
return serviceProvider.ToLower() switch
"aws" => new AwsAccountManager(),
"azure" => new AzureAccountManager(),
_ => throw new InvalidOperationException("Invalid service provider")
public struct SalesRecord
public string Item { get; set; }
public int Qty { get; set; }
public SalesRecord(string item)
public interface IAccountManager
public bool Authenticate(string userId, string password);
public class AwsAccountManager : IAccountManager
private readonly AwsService _awsService;
public AwsAccountManager()
_awsService = new AwsService();
public bool Authenticate(string userId, string password)
return _awsService.Authenticate(userId, password);
public class AzureAccountManager : IAccountManager
private readonly AzureService _azureService;
public AzureAccountManager()
_azureService = new AzureService();
public bool Authenticate(string userId, string password)
return _azureService.AuthUser(userId, password);
public bool Authenticate(string userId, string password)
return userId == "aws" && password == "abc123";
public bool DeleteUser(string userId)
public class AzureService
public bool AuthUser(string userId, string password)
return userId == "azure" && password == "abc321";
public bool RemoveUser(string userId)