AuthorSolution

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

namespace Exam
{
   public class Fridge
    {
        private Product head;
        private Product tail;
        private int count;

        private class Product
        {
            private string name;
            private Product next;

            public Product(string name)
            {
                this.name = name;
            }

            public string Name
            {
                get { return name; }
                set { name = value; }
            }

            public Product Next
            {
                get { return next; }
                set { next = value; }
            }

            public override string ToString()
            {
                return "Product " + name;
            }
        }

        public Fridge()
        {

        }

        public int Count
        {
            get { return count; }
            set { count = value; }
        }

        public void AddProduct(string ProductName)
        {
            Product Product = new Product(ProductName);

            if (this.head == null)
            {
                this.head = Product;
                this.tail = Product;
            }
            else
            {
                Product currentLast = this.tail;
                currentLast.Next = Product;
                this.tail = Product;
            }
            this.Count++;
        }

        public string[] CookMeal(int start, int end)
        {
            int count = 0;
            List<string> usedProducts = new List<string>();

            Product current = this.head;

            while (current != null && count < end)
            {
                if (count >= start)
                {
                    usedProducts.Add(current.Name);
                }

                current = current.Next;
                count++;
            }
            return usedProducts.ToArray();
        }

        public string RemoveProductByIndex(int index)
        {
            int count = 0;
            Product current = this.head;

            while (current != null)
            {
                if (index == 0)
                {
                    this.head = current.Next;
                    this.Count--;
                    return current.Name;
                }

                if (count + 1 == index)
                {
                    String name = current.Next.Name;

                    if(current.Next.Next == null)
                    {
                        this.tail = current;
                        this.Count--;
                        current.Next = null;
                        return name;
                    }

                    current.Next = current.Next.Next;
                    this.Count--;

                    return name;
                }

                current = current.Next;
                count++;
            }
            return null;
        }

        public string RemoveProductByName(string name)
        {
            Product current = this.head;

            while (current != null)
            {
                if (current.Name == name)
                {
                    this.head = current.Next;
                    this.Count--;
                    return current.Name;
                }

                if (current.Next.Name == name)
                {
                    if (current.Next.Next == null)
                    {
                        this.tail = current;
                        this.Count--;
                        current.Next = null;
                        return name;
                    }

                    current.Next = current.Next.Next;
                    this.Count--;

                    return name;
                }
                current = current.Next;
            }
            return null;
        }

        public bool CheckProductIsInStock(string name)
        {
            Product current = this.head;

            while (current != null)
            {
                if (current.Name == name)
                {
                    return true;
                }

                current = current.Next;
            }
            return false;
        }

        public string[] ProvideInformationAboutAllProducts()
        {
            String[] info = new string[this.Count];
            int index = 0;

            Product current = this.head;

            while (current != null)
            {
                info[index++] = current.ToString();
                current = current.Next;
            }

            return info;
        }
    }
}