finding shortest path

[aleya]

I am developing a program using VB.NET that will accept a start and end
location (2 list boxes), the system then will generate the shortest path to reach the end point.
for your information i got a code in C and succesfully translated it into vb.net. however this code had fix the length during the declaration. what i want to do now is keep the distances in database (sql server) and during calculation it'll retrieve data from database.i had create the database in sql server. the problem now is how to start the calculation. Anyone here have idea on doing this or some code examples that can share it with me. how could i edit these code into something like that. please help me since i am new with this.

Thanks in advance.

below is the code i had translated from C to vb.net. i want to get the output just like the code velow. ikindly please guide and help me.

Public Class WebForm1
Inherits System.Web.UI.Page
 
Public Const VERTEXNUM As Integer = 4
Public Const HUGE As Integer = 32000
Public Shared vertices() As String = {"Bukit Bintang", "China Town", "Chow Kit", "Istana Negara"}
 
Public Shared edges(,) As Double = {{0, 0.9, 2.1, 3.1}, {0.9, 0, 2.2, 1.4}, {2.1, 2.2, 0, 3.4}, {3.1, 1.4, 3.4, 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
 
 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
 
'changing line as follows will allow all 7 lines to be printed in WinForms application
 
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
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 Integer)
 
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

[kenobewan]

Still unsure where the problem lies, you are having trouble using foundHamiltonian?

[aleya]

what i mean is...i had kept the distance and edges in database. right now is i want to adjust the code just like mapping system. there will be start and end location user could select ( 2 list boxes)..and then once calculate button is clicked...system will run the code. it different from what i do now since the code above i set the distance and vertices in the code, not in the database.
how could i adjust the code that could integrate with the sql database created? i wish to get the output same as the code that i paste above. please help me with this

[kenobewan]

If you are going to use a database, then you have use a connection and queries. Here is a good place to start with a connection string.

[aleya]

i have a question here.i want to increase the number of location(vertexnum) involve to 15. firstly i up the number of location to 5. but the output doesnt show up. what should i change instead of the value of VERTEXNUM, edges and vertices?

[aleya]

i have a question here.i want to increase the number of location(vertexnum) involve to 15. firstly i up the number of location to 5. but the output doesnt show up. what should i change instead of the value of VERTEXNUM, edges and vertices?