how do i write this for vb.net

Yes your result same as mine. Supposedly the start location is the KL Tower since I set the start value to 1.8, not the Chow Kit. The problem lies here and I am not sure what goes wrong.

I've been through the code and the only lines where I differed from yours were these:

Public visited(VERTEXNUM - 1) As Integer

Thank you for your reply. Actually I had changed the places and distances. The distance now involve decimal number, so I use double as the data type. Therefore few changes had to be done in order to get the result in decimal also. No problem arise when number of places is 4, but once I add one more place, and set the start value to the new location, the output goes wrong. I plan to set until 15 locations. Here I attached the code.

Public Class WebForm1

Inherits System.Web.UI.Page

Public Const VERTEXNUM As Integer = 5

Public Const HUGE As Integer = 32000

Public Shared vertices() As String = {"Bukit Bintang", "China Town", "Chow Kit", "Istana Negara", "KL Tower"}

'distance in kilometre(s)

Public Shared edges(,) As Double = {{0, 0.9, 2.1, 3.1, 1.8}, {0.9, 0, 2.2, 1.4, 1.9}, {2.1, 2.2, 0, 3.4, 1.6}, {3.1, 1.4, 3.4, 0, 4.6}, {1.8, 1.9, 1.6, 4.6, 0}}

Public visited(VERTEXNUM) As Integer

Public curMinCost As Double = HUGE

Public curMinHamNum As Integer = 0

Public currentRoute(VERTEXNUM) As Integer

Public Function main() As Double

Dim start As Double = 1.8

Dim j As Integer

For j = 0 To VERTEXNUM - 1

If (j <> start) Then

findRoute(start, j, edges(start, j), 0)

End If

Next j

TextBox1.Text &= "lowest cost hamiltonian cycle: " & curMinHamNum & " w/ cost " & curMinCost & Environment.NewLine

Return 0

End Function

Public Sub findRoute(ByVal start As Integer, ByVal current As Integer, ByVal costSoFar As Double, ByVal numVisited As Integer)

Dim j As Integer

currentRoute(numVisited) = current

If (current = start) Then

If (numVisited = VERTEXNUM - 1) Then

foundHamiltonian(start, costSoFar + edges(current, start))

End If

Else

visited(current) = 1

For j = 0 To VERTEXNUM - 1

If (visited(j) = 0) Then

findRoute(start, j, costSoFar + edges(current, j), numVisited + 1)

End If

Next j

visited(current) = 0

End If

End Sub

Public Sub foundHamiltonian(ByVal start As Integer, ByVal cost As Double)

Dim j As Integer

Static hamNum As Integer = 0

hamNum = hamNum + 1

TextBox1.Text &= "#:" & hamNum & " " & vertices(start)

For j = 0 To VERTEXNUM - 1

TextBox1.Text &= "->" & vertices(currentRoute(j))

Next j

TextBox1.Text &= "costs " & cost & Environment.NewLine

If (cost < curMinCost) Then

curMinCost = cost

curMinHamNum = hamNum

End If

End Sub

End Class

As u can see, the fist value in each curly bracket, represent each location involve. When I set the start value to 1.8 the result display that the start location is China Town. I got confuse here, and try to make changes here and there, but it wont work. Maybe the data type that I used effect the way value passes along the functions.

As far as I can see, you don't have anything hard-coded in there which would prevent the code from being generalized to cope with more than 4 vertices, provided you change VERTEXNUM and the vertices and edges arrays appropriately.

Also, whilst I don't understand why you would want to change 'start' to a Double rather than an Integer, I don't see that this would actually make any difference to the output because of VB.Net's numeric type coercion rules.

Can you let me know what values you're using and what the output should be (as per the C program) and I'll take a look at it.

Oh you are right Alan. I missed look the concatenate symbol at the function main. Thank you so much. It works.By the way there are so much more to learn :D

That's strange, it should work OK :-/

Did you remember to concatenate each line to what's already in the TextBox's Text property (using the &= operator) as I did ?  If you don't do that, then it will overwrite it each time a line is written.

The alternative would be to use the ListBox control.

I had set the textmode to multiline but still it could not display all 7 lines of output. Is there any other way that could display the output?

Sorry, I'm talking nonsense about the ASP.Net TextBox not being able to display multiple lines. You just need to set the TextMode property to TextBoxMode.MultiLine.

I actually tested the revised code in a WinForms application where I needed to set the TextBox's  Multiline property, and change its dimensions, to display all 7 lines. I then put the code back  into a web form class as you had it but couldn't then find the Multiline property, forgetting that things are done a little differently in ASP.Net :)

So do you mean that even the textline is set to multiline, but still it could not display all 7 lines? There might be a way at least could display the final result including the roads involved with the final result. Anyway thank you because finally it works

I've been through it all again and found a number of suble errors in the VB translation which were preventing it from working properly.

The only problem with having a Web app rather than a Windows Forms app is that the former doesn't have a multiline TextBox and so can only show the final rather than all seven lines of output.

Anyway, here's the working version. I've stuck as closely as possible to the original C code and so I've set VERTEXNUM = 4 and got rid of the temporary variables:

Public Class WebForm1

    Inherits System.Web.UI.Page

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

End Sub

Public Function  main() As Integer

Dim start As Integer = 0

Dim j As Integer

For j = 0 To VERTEXNUM - 1

If (j <> start) Then

End If

Next j

TextBox1.Text = "lowest cost hamiltonian cycle: " & curMinHamNum & " w/ cost " & curMinCost & Environment.NewLine

'changing line as follows will allow all 7 lines to be printed in WinForms application

'TextBox1.Text &= "lowest cost hamiltonian cycle: " & curMinHamNum & " w/ cost " & curMinCost & Environment.NewLine

Return 0

End Function

Public Sub findRoute(ByVal start As Integer, ByVal current As Integer, ByVal costSoFar As Integer, ByVal numVisited As Integer)

Dim j As Integer

If (current = start) Then

If (numVisited = VERTEXNUM - 1) Then

End If

Else

For j = 0 To VERTEXNUM - 1

If (visited(j) = 0) Then

End If

Next j

End If

End Sub

Public Sub foundHamiltonian(ByVal start As Integer, ByVal cost As Integer)

Dim j As Integer

Static hamNum As Integer = 0

TextBox1.Text &= "#:" & hamNum & " " & vertices(start)

For j = 0 To VERTEXNUM - 1

TextBox1.Text &= "->" & vertices(currentRoute(j))

Next j

TextBox1.Text &= "costs " & cost & Environment.NewLine

If (cost < curMinCost) Then

End If

End Sub

End Class

Dear alan, I had changed the code as your suggestion but still the output is not like what the C codes display

Ø      Is this because I make the project as web application but not windows application. Does this make any sense that cause the code doesn’t work?

      Ø      the output that I try on the C code shows this

      #1: selandar->chinchin->jasin->merlimau->selandar costs 90
#2:…
…
Lowest cost Hamiltonian cycle: 2 w/ cost 85

Ø      It seems like the calling procedures doesn’t work because the output I got after   modification is this

 lowest cost hamiltonian cycle: 0 w/ cost 32000

I've compared the two and the main things I noticed are:

1. The vertices array should be of String rather than Char type.

2. Having changed the VERTEXNUM constant from 4 to 3, you've then overlooked this in some For statements and iterated up to 2 rather than 3.

3. You've tried to simplify some code within loops by assigning certain expressions to variables but have overlooked in some cases that the expressions depended on the loop variable itself.

Here's what I think the corrected VB code should be:

Public Class WebForm1

    Inherits System.Web.UI.Page

    Public Const VERTEXNUM As Integer = 3
    Public Const HUGE As Integer = 32000
    Public Shared vertices() As String = {"Selandar", "ChinChin", "Jasin", "Merlimau"} ' changed Char to String
    Public Shared edges(,) As Integer = {{0, 22, 16, 32}, {22, 0, 15, 26}, {16, 15, 0, 21}, {32, 26, 21, 0}}

    Public visited(VERTEXNUM) As Integer
    Public curMinCost As Integer = HUGE

    Public curMinHamNum As Integer = 0
    Public currentRoute(VERTEXNUM) As Integer

  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        main()

    End Sub

    Public Function main() As Integer

        Dim start As Integer = 0
        'Dim j As Integer  ' not needed
        'Dim x As Integer = edges(start, j) 'not needed

        For j = 0 To 3 ' changed 2 to 3
            If (j <> start) Then
                findRoute(start, j, edges(start,j), 0)  'replaced x
                TextBox1.Text = "lowest cost hamiltonian cycle: "  & curMinHamNum & " w/ cost " &  curMinCost 'several minor changes here
                Return 0
            End If
        Next j

    End Function

    Public Sub findRoute(ByVal start As Integer, ByVal current As Integer, ByVal costSoFar   As Integer, ByVal numVisited As Integer)

        Dim j As Integer
        Dim w As Integer = numVisited + 1
        Dim y As Integer = costSoFar + edges(current, start)
        'Dim z As Integer = costSoFar + edges(current, j) 'not needed

        currentRoute(numVisited) = current

        If (current = start) Then
            If (numVisited = VERTEXNUM) Then ' removed  -1
                foundHamiltonian(start, y)
            Else
                visited(current) = 1
                For j = 0 To 3  ' changed 2 to 3
                    If (Not visited(j)) Then
                        findRoute(start, j, costSoFar + edges(current, j), w) 'replaced z
                    End If
                Next j
                visited(current) = 0
            End If
        End If
    End Sub

    Public Sub foundHamiltonian(ByVal start As Integer, ByVal cost As Integer)

        Dim j As Integer
        Static hamNum As Integer = 0

        hamNum = hamNum + 1
        TextBox1.Text = "#:" & hamNum & " " & vertices(start) ' changed "" to " "

        For j = 0 To 3 ' changed 2 to 3
            TextBox1.Text = "->" & vertices(currentRoute(j))
        Next j

        'TextBox1.Text = "costs " & cost 'inserted space after costs

        If (cost < curMinCost) Then
            curMinCost = cost
            curMinHamNum = hamNum
        End If

    End Sub

End Class