Problem 7. Car Salesman

Program.cs

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

namespace Exercises
{
    class Program
    {
        static void Main(string[] args)
        {
           
            for (int i = 0; i < 2; i++)
            {
                int n = Convert.ToInt32(Console.ReadLine());

                for (int j = 0; j < n; j++)
                {
                    Queue<string> input = new Queue<string>(Console.ReadLine().Split());
                    if (i == 0) // Engines input
                    {
                        string model = input.Dequeue();
                        int power = Convert.ToInt32(input.Dequeue());
                        int displacement = -1;
                        string efficiency = "n/a";

                        if (input.Count > 0)
                        {
                            if (input.Peek().Any(char.IsDigit))
                            {
                                displacement = Convert.ToInt32(input.Dequeue());
                            }

                            if (input.Count > 0)
                            {
                                if (input.Peek().Any(char.IsLetter))
                                {
                                    efficiency = input.Dequeue();
                                }
                            }
                        }

                        new Engine(model, power, displacement, efficiency);
                    }
                    else // Cars input
                    {
                        string model = input.Dequeue();
                        string engineModel = input.Dequeue();
                        Engine engine = Engine.FindEngine(engineModel);
                        string color = "n/a";
                        int weight = -1;

                        if (input.Count > 0)
                        {
                            if (input.Peek().Any(char.IsDigit))
                            {
                                weight = Convert.ToInt32(input.Dequeue());
                            }

                            if (input.Count > 0)
                            {
                                if (input.Peek().Any(char.IsLetter))
                                {
                                    color = input.Dequeue();
                                }
                            }
                        }
                        new Car(model, weight, color, engine);

                    }

                }
            }

            Car.PrintCars();
        }

        class Car
        {
            private string _model;
            private int _weight = -1;
            private string _color = "n/a";
            private Engine _engine;
            private static readonly List<Car> Cars = new List<Car>();

            public Car(string model, int weight, string color, Engine engine)
            {
                _model = model;
                _weight = weight;
                _color = color;
                _engine = engine;

                Cars.Add(new Car(_model, _engine, _weight, _color));
                
            }

            private Car(string model, Engine engine, int weight, string color)
            {
                _model = model;
                _engine = engine;
                _weight = weight;
                _color = color;
            }

            public static void PrintCars()
            {
                Cars.ForEach(c => Console.WriteLine(c.ToString()));
            }

            public override string ToString()
            {
                dynamic weight = _weight == -1 ? (dynamic) "n/a" : _weight;
                return $"{_model}:\n  {_engine.ToString()}\n  Weight: {weight}\n  Color: {_color}";
            }

        }

        class Engine
        {
            private string _model;
            private int _power;
            private int _displacement = -1;
            private string _efficiency = "n/a";
            private static readonly List<Engine> Engines = new List<Engine>();

            public Engine(string model, int power, int displacement, string efficiency)
            {
                _model = model;
                _power = power;
                _displacement = displacement;
                _efficiency = efficiency;

                Engines.Add(new Engine(_power, _model, _displacement, _efficiency));
            }

            private Engine(int power, string model, int displacement, string efficiency)
            {
                _power = power;
                _model = model;
                _displacement = displacement;
                _efficiency = efficiency;
            }

            public static Engine FindEngine(string model)
            {
                return Engines.First(e => e._model == model);
            }

            public override string ToString()
            {
                dynamic displacement = _displacement == -1 ? (dynamic) "n/a" : _displacement;
                return $"{_model}:\n    Power: {_power}\n" +
                       $"    Displacement: {displacement}\n    Efficiency: {_efficiency}";
            }
        }
    }

}