ReversedList

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace demo
{
    class ReversedList
    {
        private const int DefaultCapacity = 2;
        private const int DefaultExtendMultiplier = 2;


        private object[] elements;
        private object[] reversedElements;
        private int count;
        public int Capacity { get; set; }

        public ReversedList()
        {
            this.elements = new object[0];
            this.reversedElements = new object[0];
            this.count = 0;
            Capacity = 0;
        }

        public object this[int index]
        {
            get { return reversedElements[index]; }
            set { reversedElements[index] = value; }
        }

        public int Count
        {
            get { return count; }
        }

        public void Add(object obj)
        {
            if (count == 0)
            {
                elements = new object[DefaultCapacity];
                Capacity = DefaultCapacity;
            }
            else if (count == Capacity)
            {
                ExtendElementsContainer();
            }

            elements[count] = obj;
            count++;

            reversedElements = getReversed(elements);
        }

        public void RemoveAt(int index)
        {
           reversedElements = getReversed(elements);
            if (index < 0 || index >= reversedElements.Length)
            {
                throw new ArgumentOutOfRangeException("Argument is out of range");
            }

            for (int i = index; i < count; i++)
            {
                reversedElements[i] = reversedElements[i + 1];
            }
            reversedElements[count] = null;
            count--;
        }

        private void ExtendElementsContainer()
        {
            var newContainer = new object[elements.Length * DefaultExtendMultiplier];
            Capacity = newContainer.Length;

            for (int i = 0; i < elements.Length; i++)
            {
                newContainer[i] = elements[i];
            }

            elements = newContainer;
        }

        private object[] getReversed(object[] elements)
        {
            //[1, 3, 4, 7] -> [7, 4, 3, 1]
            object[] reversed = new object[elements.Length];
            int indexReversed = 0;
            for (int i = elements.Length - 1; i >= 0; i--)
            {
                object currentElement = elements[i];
                reversed[indexReversed] = currentElement;
                indexReversed++;
            }

            return reversed;
        }
    }
}