using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Choose Options: 1- Method Overloading \t 2- Method Overriding");

            int options = Convert.ToInt32(Console.ReadLine());

            switch (options) {

                case 1:

                    #region Compile Time

                    MethodOverloading mo = new MethodOverloading();

                    mo.Fibonacci();

                    Console.WriteLine("Enter a number:");

                    mo.Fibonacci(Convert.ToInt32(Console.ReadLine()));

                    #endregion

                    break;

                case 2:

                    #region Run Time

                    Company co = new Company();

                    Console.WriteLine("Enter an Employee ID:");

                    co.GetEmployee(Convert.ToInt32(Console.ReadLine()));

                    #endregion

                    break;

            }

    }

}

//----------------------------<*>-------------------------------

#region Method Overloading

    class MethodOverloading

    {

        public void Fibonacci() {

            int a = 0, b = 1, c = 0, len = 10;

            Console.Write($"{a} {b} ");

            for (int i = 2; i < len; i++) {

                c = a + b;

                Console.Write($" {c}");

                a = b;

                b = c; 

            }

            Console.Write("\n");

        }

        public void Fibonacci(int len)

        {

            int a = 0, b = 1, c = 0;

            Console.Write($"{a} {b} ");

            for (int i = 2; i < len; i++)

            {

                c = a + b;

                Console.Write($" {c}");

                a = b;

                b = c;

            }

            Console.Write("\n");

        }

    }

    #endregion

    #region Method Overidding

    class Employee {

        public int EmployeeID { get; set; }

        public string Name { get; set; }

        public string Department { get; set; }

        public string Designation { get; set; }

        List<Employee> li_ = new List<Employee>();

​

        public List<Employee> GetEmployees() {

            Employee e_ = new Employee() {

                EmployeeID = 1001,

                Name = "XXXXX",

                Department = "IT",

                Designation = "Software Engineer"

            };

            li_.Add(e_);

            Employee e__ = new Employee()

            {

                EmployeeID = 1002,

                Name = "YYYYYY",

                Department = "Accounts",

                Designation = "Accountant"

            };

            li_.Add(e__);

            return li_;

        }

        public virtual void GetEmployee(int Id) { }

    }

    sealed class Company : Employee

    {

        public override void GetEmployee(int Id)

        {

            List<Employee> li = GetEmployees();

            foreach (var item in li.Where(x => x.EmployeeID == Id)) {

                    Console.WriteLine($"Employee ID: {item.EmployeeID} \n");

                    Console.WriteLine($"Employee Name: {item.Name} \n");

                    Console.WriteLine($"Department: {item.Department}");

                    Console.WriteLine($"Department: {item.Designation}");

                    Console.WriteLine("----------------------\n");

            }

​

        }

    }

    #endregion