using System;  

public class ArrayExample  

{  

​

    public static void Main(string[] args)  

    {

     int a, b;

      PhanSo phanso1 = new PhanSo { TuSo = 10, MauSo = 4 };

      PhanSo phanso2 = new PhanSo { TuSo = 3, MauSo = 7 };            

      Console.WriteLine("Phan so thu nhat = {0}", phanso1); 

      Console.WriteLine("Phan so thu hai = {0}", phanso2);

​

      int chon;

      do

​

      {

​

          Console.WriteLine("******************************************************");

          Console.WriteLine("                         MENU");

          Console.WriteLine("   1. Tong");

          Console.WriteLine("   2. Hieu");

          Console.WriteLine("   3. Tich");

          Console.WriteLine("   4. Thuong");

          Console.WriteLine("   5. Cong phan so hien hanh voi mot so nguyen");

          Console.WriteLine("   6. Cong phan so hien hanh voi mot phan so khac");

          Console.WriteLine("   7. Rut gon phan so");

          Console.WriteLine("   8. So sanh 2 phan so");

          Console.WriteLine("   9. Thoat");

          chon = Int32.Parse(Console.ReadLine());

          switch (chon)

​

          {

​

             case 1:

                  {                    

                     Console.Write("Tong cua hai phan so : ");

                     Console.WriteLine(phanso1 + phanso2);

                     break;

                  }

​

             case 2:

                  {

                      Console.Write("Hieu cua hai phan so :");

                      Console.WriteLine(phanso1 - phanso2);

                      break;

                  }

​

             case 3:

                  {                           

                      Console.Write("Hieu cua hai phan so :");

                      Console.WriteLine(phanso1 * phanso2);

                      break;

                  }

​

             case 4:

                  {                        

                      Console.Write("Hieu cua hai phan so :");

                      Console.WriteLine(phanso1 / phanso2);

                      break;

                  }

​

              case 5:

                  {

                      Console.Write("Phan so hien hanh la: ");

                      Console.WriteLine(phanso1);

                      Console.Write("Nhap vao so nguyen a = ");

                      a = Int32.Parse(Console.ReadLine());

                      PhanSo phanso3 = new PhanSo { TuSo=a};

                      Console.Write("Tong cua so phan so hien hanh va so nguyen a =  " + a + " la:  ");

                      Console.WriteLine(phanso1 + phanso3);

                      break;

                  }

​

              case 6:

                  {

                      Console.Write("Phan so hien hanh la: {0} ", phanso1);                        

                      Console.WriteLine("Nhap mot phan so:");

                      Console.Write("Nhap vao tu so: ");

                      a = Int32.Parse(Console.ReadLine());

                      Console.Write("Nhap vao mau so: ");

                      b = Int32.Parse(Console.ReadLine());

                      PhanSo psk = new PhanSo { TuSo =a , MauSo = b };                        

                      Console.Write("Tong cua phan so hien hanh voi phan so " + a + "/" + b + " la:");

                      Console.WriteLine(phanso1 + psk); 

                      break;

                  }

​

             case 7:

                  {

                      Console.Write("Phan so can rut gon: ");

                      Console.WriteLine(phanso1);                   

                      Console.WriteLine();

                      Console.Write("Phan so sau khi rut gon: ");

                      phanso1.RutGon();

                      Console.WriteLine(phanso1);

                      break;

​

                  }

​

              case 8:

                  {

                      if(phanso1.SoSanh(phanso2))

                          Console.WriteLine("phan so" + phanso1+ " lon hon phan so " + phanso2);

                      else

                          Console.WriteLine("phan so" + phanso1 + " nho hon phan so " + phanso2);

                      break;

                  }

              case 9: goto ketthuc;

​

          }

​

      }

​

      while (chon != 9);

​

      Console.ReadLine();

​

    ketthuc:;            

    }

     class PhanSo

    {

        private int _TuSo, _MauSo;

        public PhanSo()

        {

            this._MauSo = 1;

        }

        public int TuSo

        {

            get

            {

                return this._TuSo;

            }

            set

            {

                this._TuSo = value;

            }

        }

        public int MauSo

        {

            get

            {

                return this._MauSo;

            }

            set

            {

                try

                {

                    if (value == 0)

                    {

                        Exception MauBangKhong = new Exception("Mau phai khac 0");

                        throw MauBangKhong;

                    }

                    else

                    {

                        this._MauSo = value;

                    }

                }

                catch (Exception e)

                {

                    Console.WriteLine(e);

                    throw e;

                }

            }

        }

        public void RutGon()

        {

            int a = this.TuSo;

            int b = this.MauSo;

            int ucln;

            if (a < 0)

            {

                a = a * (-1);

            }

            if (b < 0)

            {

                b = b * (-1);

            }

            if (a == 0)

            {

                ucln = a + b;

            }

            while (a != b)

            {

                if (a > b)

                {

                    a -= b;

                }

                else

                {

                    b -= a;

                }

            }

            ucln = a;

            this.TuSo /= ucln;

            this.MauSo /= ucln;

        }

        public static PhanSo operator +(PhanSo a, PhanSo b)

        {

            PhanSo c = new PhanSo();

            c.MauSo = a.MauSo * b.MauSo;

            c.TuSo = a.TuSo * b.MauSo + b.TuSo * a.MauSo;

            c.RutGon();

            return c;

        }

        public static PhanSo operator -(PhanSo a, PhanSo b)

        {

            PhanSo c = new PhanSo();

            c.MauSo = a.MauSo * b.MauSo;

            c.TuSo = a.TuSo * b.MauSo - b.TuSo * a.MauSo;

            c.RutGon();

            return c;

        }

        public static PhanSo operator *(PhanSo a, PhanSo b)

        {

            PhanSo c = new PhanSo();

            c.MauSo = a.MauSo * b.MauSo;

            c.TuSo = a.TuSo * b.TuSo;

            c.RutGon();

            return c;

        }

        public static PhanSo operator /(PhanSo a, PhanSo b)

        {

            PhanSo c = new PhanSo();

            try

            {

                if (b.TuSo == 0)

                {

                    Exception ThuongBangKhong = new Exception("Thuong phai khac 0");

                    throw ThuongBangKhong;

                }

                else

                {

                    c.TuSo = a.TuSo * b.MauSo;

                    c.MauSo = a.MauSo * b.TuSo;

                    c.RutGon();

                    return c;

                }

            }

            catch (Exception e)

            {

                Console.WriteLine(e);

                throw e;

            }

        }

        public double Giatri()

        {

            return Convert.ToDouble(this.TuSo) / Convert.ToDouble(this.MauSo);

        }

        public override string ToString()

        {

            return Convert.ToString(this.TuSo) + "/" + Convert.ToString(this.MauSo);

        }

        public bool SoSanh(PhanSo a) // so sanh 2 phan so. neu >  la true, nguoc lai < la false.

        {

            float x;

            float y;

            if (MauSo != a.MauSo)

            {

                x = TuSo * a.MauSo;

                y = MauSo * a.TuSo;

            }

            else

            {

                y = TuSo;

                x = a.TuSo;

            }

            if (x > y)

                return true;

            return false;

        }

     }

}