using System;
using System.Collections.Generic;
 
public class ProgrammingLanguagesLinkedList
{
    public static void Main()
    {
        Console.WriteLine("Programming Languages LinkedList Demo:");
        Console.WriteLine("=====================================");
 
        // Create a new LinkedListNode and display its properties
        LinkedListNode<string> centerNode = new LinkedListNode<string>("Java");
        Console.WriteLine("After creating the 'Java' node:");
        DisplayNodeProperties(centerNode);
 
        // Create a new LinkedList
        LinkedList<string> languageList = new LinkedList<string>();
 
        // Add the "Java" node to the list
        languageList.AddLast(centerNode);
        Console.WriteLine("After adding Java node to the empty LinkedList:");
        DisplayNodeProperties(centerNode);
 
        // Add nodes before and after the "Java" node
        languageList.AddFirst("Python");
        languageList.AddLast("C#");
        languageList.AddAfter(centerNode, "JavaScript");
        languageList.AddBefore(centerNode, "C++");
 
        Console.WriteLine("After adding Python, C#, JavaScript, and C++:");
        DisplayNodeProperties(centerNode);
 
        Console.WriteLine("\nComplete LinkedList traversal (first to last):");
        foreach (string language in languageList)
        {
            Console.WriteLine("Language: " + language);
        }
 
        Console.WriteLine("\nLinkedList navigation demonstration:");
        Console.WriteLine("First language: " + languageList.First.Value);
        Console.WriteLine("Last language: " + languageList.Last.Value);
        Console.WriteLine("Second language: " + languageList.First.Next.Value);
        Console.WriteLine("Second to last language: " + languageList.Last.Previous.Value);
 
        // Remove a language and show the effect
        languageList.Remove("C++");
        Console.WriteLine("\nAfter removing C++:");
        DisplayNodeProperties(centerNode);
 
        Console.WriteLine("\nFinal LinkedList:");
        foreach (string language in languageList)
        {
            Console.WriteLine("Language: " + language);
        }
 
        Console.WriteLine("\nTotal languages in LinkedList: " + languageList.Count);
    }
 
    public static void DisplayNodeProperties(LinkedListNode<string> node)
    {
        if (node.List == null)
            Console.WriteLine("  Node is not linked to any list.");
        else
            Console.WriteLine("  Node belongs to a linked list with {0} elements.", node.List.Count);
 
        if (node.Previous == null)
            Console.WriteLine("  Previous node is null.");
        else
            Console.WriteLine("  Value of previous node: {0}", node.Previous.Value);
 
        Console.WriteLine("  Value of current node: {0}", node.Value);
 
        if (node.Next == null)
            Console.WriteLine("  Next node is null.");
        else
            Console.WriteLine("  Value of next node: {0}", node.Next.Value);
 
        Console.WriteLine();
    }
}

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