using System;

using System.Collections.Generic;

​

namespace Stacks

{

    public delegate void StackEventHandler(object source, StackEventArgs e);

​

    class Program

    {

        static void Main(string[] args)

        {

            var stack = new GenericStack<int>();

​

            var myStack = new StackEventHandlers();

​

            stack.PushEvent += myStack.OnPushEvent;

            stack.PopEvent += myStack.OnPopEvent;

​

            stack.Push(2);

            stack.Push(13);

            stack.Push(24);

            stack.Push(35);

            stack.Push(46);

            stack.Push(57);

            stack.Push(68);

            stack.Push(79);

​

            var item = stack.Pop();

            Console.WriteLine(item);

            item = stack.Pop();

            Console.WriteLine(item);

            item = stack.Pop();

            Console.WriteLine(item);

​

            stack.Push(100);

            item = stack.Pop();

            Console.WriteLine(item);

​

        }

    }

​

    public class StackEventHandlers

    {

        public void OnPushEvent(object source, StackEventArgs e)

        {

            Console.WriteLine($"Yay! Pushed on {e.Top}");

        }

​

        public void OnPopEvent(object source, StackEventArgs e)

        {

            Console.WriteLine($"Darn! Popped from {e.Top}");

        }

    }

    public class GenericStack<T>

    {

        public event StackEventHandler PushEvent;

        public event StackEventHandler PopEvent;

​

        private readonly List<T> stack = new List<T>();

        private int _top = -1;

​

        public void Push(T element)

        {

            _top++;

            stack.Add(element);

            RaisePushEvent(_top);

        }

​

        public T Pop()

        {

            T element = stack[_top];

            stack.Remove(stack[_top]);

            _top--;

            RaisePopEvent(_top + 1);

            return element;

        }

​

        protected virtual void RaisePushEvent(int top)

        {

            if (PushEvent != null)

            {

                PushEvent(this, new StackEventArgs(top));

            }

        }

​

        protected virtual void RaisePopEvent(int top)

        {

            if (PopEvent != null)

            {

                PopEvent(this, new StackEventArgs(top));

            }

        }

    }

​

    public class StackEventArgs : EventArgs

    {

        public int Top { get; set; }

​

        public StackEventArgs(int top)

        {

            Top = top;

        }

    }

}

​