using System;

namespace LR_26_12

{

public class Program

{

    public static void Main()

    {

        //1

            Article article = new Article("Гроза", "Иванов", 2000);

            Article article1 = new Article();

            //явный вызов

            Console.WriteLine(article.ToString());

            //неявный вызов

            Console.WriteLine(article1);

​

        //2

            if (article.Equals(article1))

            {

                Console.WriteLine("Объекты одинаковы");

            }

            else

            {

                Console.WriteLine("Объекты различны");

            }

        //3

            Figure figure1 = new Square(4);

            figure1.Info();

​

    }

}

​

 class Article

    {

        public string name;

        public string autor;

        public double year;

​

        public Article(string name, string autor, double year)

        {

            this.name = name;

            this.autor = autor;

            this.year = year;

        }

​

        public Article() : this("Война", "Петров", 2002)

        {

        }

​

        public override string ToString()

        {

            return "Название:{name}\nАвтор:{autor}\nГод публикации:{year}";

        }

​

        public override bool Equals(object obj)

        {

            Article article = (Article)obj;

            if (article.name == this.name && article.autor == autor && article.year == year)

            {

                return true;

            }

            else

            {

                return false;

            }

        }

    }

     abstract class Figure

    {

        public abstract string Area();

        public abstract string Perimeter();

        public abstract string Info();

        public abstract string FigureName();

    }

    class Square : Figure

    {

        public double side;

        public Square(double side)

        {

            this.side = side;

        }

​

        public override string Area()

        {

            return (side * 2).ToString();

        }

​

        public override string Perimeter()

        {

            return (side * 2).ToString();

        }

​

        public override string FigureName()

        {

            return Info();

        }

​

        public override string Info()

        {

            Console.WriteLine("Название фигуры:{FigureName()}\nПериметр{Perimeter()}\nПлощадь{Area()}");

​

            return "Квадрат";

        }

        }

        }