Imports System

​

Module Module1

​

    Sub Main()

        Dim List As New LinkedList

        Dim Input As Integer = 0

        Do While Input <> -1

            Console.Write("ENTER '1' TO ADD, '2' TO DELETE, '3' TO DISPLAY, OR '4' TO SEARCH: ")

            Input = Console.ReadLine()

            If Input < 1 Or Input > 4 Then

                Console.WriteLine("INPUT ERROR")

            ElseIf Input = 1 Then

                Console.Write("ENTER DATA TO ADD: ")

                List.Add(Console.ReadLine())

            ElseIf Input = 2 Then

                Console.Write("ENTER DATA TO DELETE: ")

                List.Delete(Console.ReadLine())

            ElseIf Input = 3 Then

                List.Display()

            End If

        Loop

    End Sub

​

    Class LinkedList

        Private Structure Node

            Dim Data As String

            Dim Pointer As Integer

        End Structure

        Private StartOfList As Integer

        Private FreePointer As Integer

        Private DataNode(9) As Node

​

        Public Sub New()

            For i = 0 To 9

                DataNode(i).Data = ""

                DataNode(i).Pointer = i + 1

            Next

            DataNode(9).Pointer = -1

            StartOfList = 0

            FreePointer = 0

        End Sub

        Public Sub Add(ByVal Input As String)

            Dim Added As Boolean = False

            FreePointer = StartOfList

            Do While FreePointer <> -1 And Added = False

                If DataNode(FreePointer).Data = "" And DataNode(FreePointer).Pointer <> -1 Then

                    DataNode(FreePointer).Data = Input

                    Added = True

                End If

                FreePointer = DataNode(FreePointer).Pointer

            Loop

        End Sub

​

        Public Sub Delete(ByVal Input As String)

            Dim CurrentNodePointer As Integer = StartOfList

            Dim Deleted As Integer = 0

            Do While CurrentNodePointer <> -1

                If DataNode(CurrentNodePointer).Data = Input Then

                    DataNode(CurrentNodePointer).Data = ""

                    Deleted += 1

                End If

                CurrentNodePointer = DataNode(CurrentNodePointer).Pointer

            Loop

            Console.WriteLine(Deleted & " AMOUNT OF DATA ARE DELETED")

        End Sub

​

        Public Sub Display()

            Dim CurrentNodePointer As Integer

            Do While CurrentNodePointer <> -1

                If CurrentNodePointer <> -1 Then

                    Console.WriteLine(DataNode(CurrentNodePointer).Data)

                    CurrentNodePointer = DataNode(CurrentNodePointer).Pointer

                End If

            Loop

        End Sub

    End Class

​

End Module