using System;

namespace TodoApplication
{
    public class LimitedSizeStack<T>
    {
        private readonly T[] array;
        private int offset = -1;
        private int count;

        public LimitedSizeStack(int limit)
        {
            array = new T[limit];
        }

        public void Push(T item)
        {
            offset++;

            count++;
            if (count > array.Length)
                count = array.Length;

            array[offset % array.Length] = item;
        }

        public T Pop()
        {
            count--;

            if (count < 0)
                throw new InvalidOperationException("stack is empty");

            var value = array[offset % array.Length];

            offset--;

            return value;
        }

        public int Count => count;
    }
}