如何使用映射文件vb.net

时间:2018-12-07 09:38:43

标签: vb.net sorting binary-search memory-mapped-files

这对我来说有点复杂

    Dim test() As Byte = New Byte() {50, 40, 30, 10, 10}
    Dim answer() As UInteger = SortLexicoGraphicallyArrayMappedFile(test)

答案是从最低数组值到最高数组值排序的每个Rotation。

Rotation 0 = 50, 40, 30, 10, 10
Rotation 1 = 10, 50, 40, 30, 10
Rotation 2 = 10, 10, 50, 40, 30
Rotation 3 = 30, 10, 10, 50, 40
Rotation 4 = 40, 30, 10, 10, 50

当我手动对数组进行排序时,我应该得到

Rotation 2 = 10, 10, 50, 40, 30
Rotation 1 = 10, 50, 40, 30, 10
Rotation 3 = 30, 10, 10, 50, 40
Rotation 4 = 40, 30, 10, 10, 50
Rotation 0 = 50, 40, 30, 10, 10

所以答案应该是2, 1, 3, 4, 0

我陷入了无限循环,无法将手指放在上面
我的上一个问题起作用了,因为这里的数据始终是静态的,我尝试在所有位置移动所有数据,这可能就是为什么它被卡住的原因,我无法找出解决方法。我需要在周围移动所有数据为了节省以后的CPU时间,这就是为什么我没有从下面的页面中选择答案的原因。

How to order array in lexicographical order vb.net

这是我的代码

Public Function GetRotation(Data As Byte(), rotation As UInteger) As Byte()
   'Rotation Left
    Dim rotationData As New List(Of Byte)

    Dim start As UInteger = Data.Length - rotation Mod Data.Length

    For i = 0 To Data.Length - 1
        rotationData.Add(Data((start + i) Mod (Data.Length)))
    Next

    Return rotationData.ToArray()
End Function

   Public Function SortLexicoGraphicallyArrayMappedFile(ByRef data As Byte()) As UInteger()
        Dim OrderedRotations As New List(Of UInteger)
        Dim rotatedData As Byte()
        Dim rotation As UInteger = 0


        Dim mmF As MemoryMappedFile
        mmF = MemoryMappedFile.CreateFromFile(My.Application.Info.DirectoryPath & "\outFile", FileMode.CreateNew, "test", CLng(data.LongLength * data.LongLength))
        Dim mmVA As MemoryMappedViewAccessor
        mmVA = mmF.CreateViewAccessor(0, data.LongLength * data.LongLength)

        Dim pos As Long = 0

        For rotation = 0 To data.Length - 1
            rotatedData = GetRotation(data, rotation)
            mmVA.WriteArray(Of Byte)(pos, rotatedData, 0, rotatedData.Length)
            pos += rotatedData.Length

        Next

        For rotation = 0 To data.Length - 1
            OrderedRotations.Add(rotation)
        Next

        Dim eachRotation As Integer = 0
        Dim data1() As Byte
        ReDim data1(data.Length - 1)
        Dim data2() As Byte
        ReDim data2(data.Length - 1)
        Dim index As Long
        For rotation = 0 To data.Length - 1
            Dim flag As Boolean
            Do
                flag = False
                For eachRotation = OrderedRotations.Count - 1 To 0 Step -1
                    mmVA.ReadArray(Of Byte)((OrderedRotations(rotation) * data.Length), data1, 0, data.Length)
                    If OrderedRotations(eachRotation) = OrderedRotations(rotation) Then Continue For
                    mmVA.ReadArray(Of Byte)((OrderedRotations(eachRotation) * data.Length), data2, 0, data.Length)

                    For index = 0 To data.Length - 1
                        If data1(index) > data2(index) Then
                            Exit For
                        ElseIf data1(index) < data2(index) Then
                            mmVA.WriteArray(Of Byte)((OrderedRotations(eachRotation) * data.Length), data1, 0, data1.Length)
                            mmVA.WriteArray(Of Byte)((OrderedRotations(rotation) * data.Length), data2, 0, data2.Length)

                            Dim tmpFirst As UInteger = OrderedRotations(rotation)
                            OrderedRotations(rotation) = OrderedRotations(eachRotation)
                            OrderedRotations(eachRotation) = tmpFirst
                            flag = True
                            Exit For
                        End If
                    Next
                Next
            Loop While flag
        Next

        Return OrderedRotations.ToArray()
    End Function

1 个答案:

答案 0 :(得分:1)

我不知道这是否正确,但我已为您修复。

Public Function SortLexicoGraphicallyArrayMappedFile(ByRef data As Byte()) As UInteger()
    Dim OrderedRotations As New List(Of UInteger)
    Dim rotatedData As Byte()
    Dim rotation As UInteger = 0


    Dim mmF As MemoryMappedFile
    mmF = MemoryMappedFile.CreateFromFile(My.Application.Info.DirectoryPath & "\outFile296", FileMode.CreateNew, "test", CLng(data.LongLength * data.LongLength))
    Dim mmVA As MemoryMappedViewAccessor
    mmVA = mmF.CreateViewAccessor(0, data.LongLength * data.LongLength)

    Dim pos As Long = 0

    For rotation = 0 To data.Length - 1
        rotatedData = GetRotation(data, rotation)
        mmVA.WriteArray(Of Byte)(pos, rotatedData, 0, rotatedData.Length)
        pos += rotatedData.Length

    Next

    For rotation = 0 To data.Length - 1
        OrderedRotations.Add(rotation)
    Next

    Dim eachRotation As Integer = 0
    Dim data1() As Byte
    ReDim data1(data.Length - 1)
    Dim data2() As Byte
    ReDim data2(data.Length - 1)
    Dim index As Long
    For rotation = 0 To data.Length - 1
        Dim flag As Boolean
        Do
            flag = False
            For eachRotation = OrderedRotations.Count - 1 To 0 Step -1
                If rotation = eachRotation Then Exit For
                mmVA.ReadArray(Of Byte)(rotation * data.Length, data1, 0, data.Length)
                mmVA.ReadArray(Of Byte)((eachRotation * data.Length), data2, 0, data.Length)

                For index = 0 To data.Length - 1
                    If data1(index) < data2(index) Then
                        Exit For
                    ElseIf data1(index) > data2(index) Then
                        mmVA.WriteArray(Of Byte)((eachRotation * data.Length), data1, 0, data1.Length)
                        mmVA.WriteArray(Of Byte)((rotation * data.Length), data2, 0, data2.Length)

                        Dim tmpFirst As UInteger = OrderedRotations(eachRotation)
                        OrderedRotations(eachRotation) = OrderedRotations(rotation)
                        OrderedRotations(rotation) = tmpFirst
                        flag = True
                        Exit For
                    End If
                Next
            Next
        Loop While flag
    Next

    Return OrderedRotations.ToArray()
End Function