using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        PatientDetails patient1 = new PatientDetails(){Name = "Venkat"};

        PatientDetails patient2 = new PatientDetails(){Name = "Anusha"};

        DoctorDetails doctor1 = new DoctorDetails(){Name = "Sai"};

        DoctorDetails doctor2 = new DoctorDetails(){Name = "Siva"};

        List<PatientDetails> lstPatients = new List<PatientDetails>(){patient1,patient2};

        List<DoctorDetails> lstDoctors = new List<DoctorDetails>(){doctor1,doctor2};

        Finder<PatientDetails> finder= new Finder<PatientDetails>();

        Console.WriteLine(finder.Find(lstPatients,"Anusha"));

    }

}

​

internal class Finder<T> 

{

   internal T Find(List<T> lst, string name)

   {

      foreach(var x in lst)

      {

        if( x is PatientDetails)

        {

            var patient = x as PatientDetails;

            if(patient.Name == name)

            {

              return (T)Convert.ChangeType(patient, typeof(T));

            }

        }

        if( x is DoctorDetails)

        {

            var doctor = x as DoctorDetails;

            if(doctor.Name == name)

            {

              return (T)Convert.ChangeType(doctor, typeof(T));

            }

        }

      }

      return default(T);

   }  

}

​

internal class PatientDetails

{

   internal string Name;

}

internal class DoctorDetails

{

   internal string Name;

}