DZSuperMarket

using System;
using System.Collections.Generic;

namespace DZSuperMarket
{
    class Program
    {
        static void Main(string[] args)
        {
            int clientsNumber = 10;
            SuperMarket superMarket = new SuperMarket();

            for (int i = 0; i < clientsNumber; i++)
                superMarket.AddClient(new Client());

            superMarket.Serve();
        }
    }

    class SuperMarket
    {
        private Queue<Client> _clients;
        private int _servedClientsCount;
        private int _balance;
        private Product[] _showcase;

        public SuperMarket()
        {
            _clients = new Queue<Client>();
            _showcase = new Product[]
            {
                new Product(80, "Хлеб"),
                new Product(250, "Сосиски"),
                new Product(120, "Шпроты"),
                new Product(100, "Кола"),
                new Product(70, "Чипсы"),
                new Product(90, "Санитайзер"),
                new Product(300, "Имбирь")
            };
        }

        public void AddClient(Client client)
        {
            client.FillCart((IReadOnlyList<Product>)_showcase);
            _clients.Enqueue(client);
        }

        public void Serve()
        {
            while(_clients.Count != 0)
            {
                Client servingClient = _clients.Dequeue();
                _servedClientsCount++;
                Console.WriteLine($"Обслуживаем клиента номер {_servedClientsCount}");
                int cartCost = servingClient.GetCartCost();
                Console.WriteLine($"Стоимость товаров в корзине: {cartCost}");
                cartCost = servingClient.PayForPurchases(cartCost);
                TakeMoney(cartCost);
                Console.WriteLine($"В кассе: {_balance}");
                Console.WriteLine();
            }
        }

        public void TakeMoney(int money)
        {
            _balance += money;
        }
    }

    class Product
    {
        public Product(int price, string name)
        {
            Price = price;
            Name = name;
        }

        public int Price { get; private set; }
        public string Name { get; private set; }
    }

    class Cart
    {
        private List<Product> _products;

        public Cart()
        {
            _products = new List<Product>();
        }

        public int GetCost()
        {
            int cost = 0;

            for (int i = 0; i < _products.Count; i++)
            {
                cost += _products[i].Price;
            }

            return cost;
        }

        public Product ExcludeProduct()
        {
            Random random = new Random();
            int excludingProductNumber = random.Next(_products.Count);
            Product excludingProduct = _products[excludingProductNumber];
            _products.RemoveAt(excludingProductNumber);
            return excludingProduct;
        }

        public void AddProduct(Product newProduct)
        {
            _products.Add(newProduct);
        }
    }

    class Client
    {
        private static Random _random;
        private Cart _shoppingCart;
        private int _money;
        private int _minBalance = 900;
        private int _maxBalance = 1900;
        private int _productsNumber = 10;

        static Client()
        {
            _random = new Random();
        }

        public Client()
        {
            _money = _random.Next(_minBalance, _maxBalance);
            _shoppingCart = new Cart();
        }

        public int GetCartCost()
        {
            return _shoppingCart.GetCost();
        }

        public void FillCart(IReadOnlyList<Product> products)
        {
            for (int i = 0; i < _productsNumber; i++)
            {
                Product desiredProduct = products[_random.Next(products.Count)];
                _shoppingCart.AddProduct(desiredProduct);
            }
        }

        public int PayForPurchases(int price)
        {
            Console.WriteLine($"У клиента {_money} денег");

            while (price > _money)
            {
                Product excludingProduct = _shoppingCart.ExcludeProduct();
                Console.WriteLine($"Из корзины убран товар {excludingProduct.Name} стоимостью {excludingProduct.Price}");
                price -= excludingProduct.Price;
            }

            Console.WriteLine($"Оплата товаров стоимостью: {price}");
            return price;
        }
    }
}