using System;

using System.Text;

using System.Collections.Generic;

​

public class Example

{

    //https://docs.microsoft.com/en-us/dotnet/api/system.collections.generic.linkedlist-1?view=netframework-4.8

    public static void Main()

    {

        // Create the link list.

        string[] words =

            { "the", "fox", "jumps", "over", "the", "dog" };

        LinkedList<string> sentence = new LinkedList<string>(words);

        Display(sentence, "The linked list values:");

        Console.WriteLine("sentence.Contains(\"jumps\") = {0}",

            sentence.Contains("jumps"));

​

        // Add the word 'today' to the beginning of the linked list.

        sentence.AddFirst("today");

        Display(sentence, "Test 1: Add 'today' to beginning of the list:");

​

        // Move the first node to be the last node.

        LinkedListNode<string> mark1 = sentence.First;

        sentence.RemoveFirst();

        sentence.AddLast(mark1);

        Display(sentence, "Test 2: Move first node to be last node:");

​

        // Change the last node to 'yesterday'.

        sentence.RemoveLast();

        sentence.AddLast("yesterday");

        Display(sentence, "Test 3: Change the last node to 'yesterday':");

​

        // Move the last node to be the first node.

        mark1 = sentence.Last;

        sentence.RemoveLast();

        sentence.AddFirst(mark1);

        Display(sentence, "Test 4: Move last node to be first node:");

​

        // Indicate the last occurence of 'the'.

        sentence.RemoveFirst();

        LinkedListNode<string> current = sentence.FindLast("the");

        IndicateNode(current, "Test 5: Indicate last occurence of 'the':");

​

        // Add 'lazy' and 'old' after 'the' (the LinkedListNode named current).

        sentence.AddAfter(current, "old");

        sentence.AddAfter(current, "lazy");

        IndicateNode(current, "Test 6: Add 'lazy' and 'old' after 'the':");

​

        // Indicate 'fox' node.

        current = sentence.Find("fox");

        IndicateNode(current, "Test 7: Indicate the 'fox' node:");

​

        // Add 'quick' and 'brown' before 'fox':

        sentence.AddBefore(current, "quick");

        sentence.AddBefore(current, "brown");

        IndicateNode(current, "Test 8: Add 'quick' and 'brown' before 'fox':");

​

        // Keep a reference to the current node, 'fox',

        // and to the previous node in the list. Indicate the 'dog' node.

        mark1 = current;

        LinkedListNode<string> mark2 = current.Previous;

        current = sentence.Find("dog");

        IndicateNode(current, "Test 9: Indicate the 'dog' node:");

​

        // The AddBefore method throws an InvalidOperationException

        // if you try to add a node that already belongs to a list.

        Console.WriteLine("Test 10: Throw exception by adding node (fox) already in the list:");

        try

        {

            sentence.AddBefore(current, mark1);

        }

        catch (InvalidOperationException ex)

        {

            Console.WriteLine("Exception message: {0}", ex.Message);

        }

        Console.WriteLine();

​

        // Remove the node referred to by mark1, and then add it

        // before the node referred to by current.

        // Indicate the node referred to by current.

        sentence.Remove(mark1);

        sentence.AddBefore(current, mark1);

        IndicateNode(current, "Test 11: Move a referenced node (fox) before the current node (dog):");

​

        // Remove the node referred to by current.

        sentence.Remove(current);

        IndicateNode(current, "Test 12: Remove current node (dog) and attempt to indicate it:");

​

        // Add the node after the node referred to by mark2.

        sentence.AddAfter(mark2, current);

        IndicateNode(current, "Test 13: Add node removed in test 11 after a referenced node (brown):");

​

        // The Remove method finds and removes the

        // first node that that has the specified value.

        sentence.Remove("old");

        Display(sentence, "Test 14: Remove node that has the value 'old':");

​

        // When the linked list is cast to ICollection(Of String),

        // the Add method adds a node to the end of the list.

        sentence.RemoveLast();

        ICollection<string> icoll = sentence;

        icoll.Add("rhinoceros");

        Display(sentence, "Test 15: Remove last node, cast to ICollection, and add 'rhinoceros':");

​

        Console.WriteLine("Test 16: Copy the list to an array:");

        // Create an array with the same number of

        // elements as the inked list.

        string[] sArray = new string[sentence.Count];

        sentence.CopyTo(sArray, 0);

​

        foreach (string s in sArray)

        {

            Console.WriteLine(s);

        }

​

        // Release all the nodes.

        sentence.Clear();

​

        Console.WriteLine();

        Console.WriteLine("Test 17: Clear linked list. Contains 'jumps' = {0}",

            sentence.Contains("jumps"));

​

        Console.ReadLine();

    }

​

    private static void Display(LinkedList<string> words, string test)

    {

        Console.WriteLine(test);

        foreach (string word in words)

        {

            Console.Write(word + " ");

        }

        Console.WriteLine();

        Console.WriteLine();

    }

​

    private static void IndicateNode(LinkedListNode<string> node, string test)

    {

        Console.WriteLine(test);

        if (node.List == null)

        {

            Console.WriteLine("Node '{0}' is not in the list.\n",

                node.Value);

            return;

        }

​

        StringBuilder result = new StringBuilder("(" + node.Value + ")");

        LinkedListNode<string> nodeP = node.Previous;

​

        while (nodeP != null)

        {

            result.Insert(0, nodeP.Value + " ");

            nodeP = nodeP.Previous;

        }

​

        node = node.Next;

        while (node != null)

        {

            result.Append(" " + node.Value);

            node = node.Next;

        }

​

        Console.WriteLine(result);

        Console.WriteLine();

    }

}

​