using System;

using System.Collections.Generic;

​

​

namespace HinhThang_Abtract

{

    abstract  class HinhKhoi2D

    {

        public abstract double DienTich();

    }

    class HinhThang : HinhKhoi2D

    {

        public double chieucao { set; get; }

        public double daylon { set; get; }

        public double daynho { set; get; }

        public HinhThang()

        {

            chieucao = 0;

            daynho = 0;

            daylon = 0;

        }

        public HinhThang(double _chieucao,double _daynho,double _daylon)

        {

            chieucao = _chieucao;

            daynho = _daynho;

            daylon = _daylon;

        }

        public override double DienTich()

        {

            return (daylon + daynho) * chieucao / 2.0;

        }

        public void Nhap()

        {

            Console.Write("Moi nhap chieu cao: ");

            chieucao = Convert.ToDouble(Console.ReadLine());

            Console.Write("Moi nhap day nho: ");

            daynho = Convert.ToDouble(Console.ReadLine());

            Console.Write("Moi nhap day lon: ");

            daylon = Convert.ToDouble(Console.ReadLine());

        }

       public static bool operator >(HinhThang ht1,HinhThang ht2)

        {

            return ht1.DienTich() > ht2.DienTich();

        }

        public static bool operator <(HinhThang ht1, HinhThang ht2)

        {

            return ht1.DienTich() < ht2.DienTich();

        }

        public static bool operator !=(HinhThang ht1, HinhThang ht2)

        {

            return ht1.DienTich() != ht2.DienTich();

        }

        public static bool operator ==(HinhThang ht1, HinhThang ht2)

        {

            return ht1.DienTich() == ht2.DienTich();

        }

    }

    class QuanLiHinh

    {

        List<HinhThang> ht;

        public QuanLiHinh()

        {

            ht =new  List<HinhThang>();

        }

        public void ThemHinh()

        {

            HinhThang tmp;

            int n;

            Console.Write("Moi ban them so luong hinh thang: ");

            n = Convert.ToInt32(Console.ReadLine());

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

            {

                tmp = new HinhThang();

                Console.WriteLine("Moi ban nhap hinh thu {0}", i + 1);

                tmp.Nhap();

                ht.Add(tmp);

            }

        }

        public void SapXep()

        {

            for (int i = 0; i < ht.Count -1; i++)

            {

                for (int j = i + 1; j < ht.Count; j++)

                {

                    if (ht[i] > ht[j])

                    {

                        HinhThang tmp = ht[i];

                        ht[i] = ht[j];

                        ht[j] = tmp;

                    }

                }

            }

            Console.WriteLine("\t\t\tDanh sach hinh thang sau khi sap xep");

            Console.WriteLine("{0 , 10}{1, 10}{2, 10}{3, 10}", "Chieu cao", "Day nho", "Day Lon", "Dien Tich");

            foreach (HinhThang item in ht)

            {

                Console.WriteLine("{0 , 10}{1, 10}{2, 10}{3, 10}", item.chieucao, item.daynho,item.daylon, item.DienTich());

            }

        }

        public void XoaHinh()

        {                 

            for (int i = 0; i < ht.Count - 1; i++)

            {

               for (int j = i +1; j < ht.Count; j++)

                {

                    if (ht[i] == ht[j])

                   {

                    ht.RemoveAt(i);

                   }

                }                             

            }

            Console.WriteLine("\t\t\tDanh sach hinh thang sau khi xoa hinh");

            Console.WriteLine("{0 , 10}{1, 10}{2, 10}{3, 10}", "Chieu cao", "Day nho", "Day Lon", "Dien Tich");

            foreach (HinhThang item in ht)

            {

                Console.WriteLine("{0 , 10}{1, 10}{2, 10}{3, 10}", item.chieucao, item.daynho, item.daylon, item.DienTich());

            }

        }

        public void HinhMoi()

        {

            HinhThang hinhmoi;

                hinhmoi = new HinhThang();

                Console.WriteLine("\t\tMoi ban them hinh moi");

                hinhmoi.Nhap();

                ht.Add(hinhmoi);

            Console.WriteLine("\t\t\tDanh sach hinh thang sau khi them hinh ");

            Console.WriteLine("{0 , 10}{1, 10}{2, 10}{3, 10}", "Chieu cao", "Day nho", "Day Lon", "Dien Tich");

            foreach (HinhThang item in ht)

            {

                Console.WriteLine("{0 , 10}{1, 10}{2, 10}{3, 10}", item.chieucao, item.daynho, item.daylon, item.DienTich());

            }

        }

    }

    class Program

    {

        static void Main(string[] args)

        {

            QuanLiHinh qlh = new QuanLiHinh();

            int luachon;

            while (true)

            {

                do

                {

                    Console.Clear();

                    Console.WriteLine("1. Them so luong hinh thang ");

                    Console.WriteLine("2. Sap xep hinh ");

                    Console.WriteLine("3. Them hinh moi ");

                    Console.WriteLine("4. Xoa hinh ");

                    Console.WriteLine("5. Thoat ");

                    Console.Write("Moi ban lua chon:(1-5) ");

                    luachon = Convert.ToInt32(Console.ReadLine());

                } while (luachon < 1 || luachon > 5);

                switch (luachon)

                {

                    case 1:

                        {

                            qlh.ThemHinh();

                            break;

                        }

                    case 2:

                        {

                            qlh.SapXep();

                            break;

                        }

                    case 3:

                        {

                            qlh.HinhMoi();

                            break;

                        }

                    case 4:

                        {

                            qlh.XoaHinh();

                            break;

                        }

                    case 5:

                        {

                            Environment.Exit(10);

                            break;

                        }

                }

                Console.WriteLine("\t\tAn phim bat ki de tiep tuc");

                Console.ReadKey();

            }

        }

    }

}

​