Minimum weight cycle in an undirected weighted graph in vb.net

Vb program for Minimum weight cycle in an undirected weighted graph. Here problem description and explanation.

' Include namespace system
Imports System 
'    Vb.net program for 
'    Minimum weight cycle in an undirected graph

Public Class AjlistNode
    '  Vertices node key
    Public  id As Integer
    Public  weight As Integer
    Public  [next] As AjlistNode
    Public Sub New(ByVal id As Integer, ByVal weight As Integer)
        '  Set value of node key
        Me.id = id
        Me.weight = weight
        Me.next = Nothing
    End Sub
End Class

Public Class Vertices
    Public  data As Integer
    Public  [next] As AjlistNode
    Public  last As AjlistNode
    Public Sub New(ByVal data As Integer)
        Me.data = data
        Me.next = Nothing
        Me.last = Nothing
    End Sub
End Class

public Class Graph
    '  Number of Vertices
    Public  size As Integer
    Public  result As Integer
    Public  node As Vertices()
    Public Sub New(ByVal size As Integer)
        '  Set value
        Me.size = size
        Me.result = 0
        Me.node = New Vertices(size){}
        Me.setData()
    End Sub
    '  Set initial node value
    Public Sub setData()
        if (Me.size <= 0) Then
            Console.WriteLine( vbLf &"Empty Graph")
        Else
            Dim index As Integer = 0
            While index < Me.size
                '  Set initial node value
                Me.node(index) = New Vertices(index)
            index += 1
            End While
        End IF
    End Sub
    
    Public Sub connection(ByVal start As Integer, 
                          ByVal last As Integer, 
                          ByVal weight As Integer)
        '  Safe connection
        Dim edge As AjlistNode = New AjlistNode(last, weight)
        if (Me.node(start).[next]  Is  Nothing) Then
            Me.node(start).[next] = edge
        Else
            '  Add edge at the end
            Me.node(start).last.[next] = edge
        End IF
        '  Get last edge 
        Me.node(start).last = edge
    End Sub
    '   Handling the request of adding new edge
    Public Sub addEdge(ByVal start As Integer, 
                       ByVal last As Integer, 
                       ByVal weight As Integer)
        if (start >= 0 AndAlso start < Me.size AndAlso 
            last >= 0 AndAlso last < Me.size) Then
            '  Connect edge with weight
            Me.connection(start, last, weight)
            Me.connection(last, start, weight)
        Else
            '  When invalid nodes
            Console.Write( vbLf &"Node missing ({0},{1})",start,last)
        End IF
    End Sub
    Public Sub printGraph()
        if (Me.size > 0) Then
            '  Print graph ajlist
            Dim index As Integer = 0
            While index < Me.size
                Console.Write( vbLf &"Adjacency list of vertex " + 
                              index.ToString() + " :")
                Dim edge As AjlistNode = Me.node(index).[next]
                while (edge IsNot Nothing)
                    '  Display graph node value and weight	
                    Console.Write("  " + Me.node(edge.id).data.ToString() + 
                                  "[" + edge.weight.ToString() + "]")
                    '  Visit to next edge
                    edge = edge.[next]
                End While
            index += 1
            End While
        End If
    End Sub
    Public Sub minimumCycle(ByVal start As Integer, 
                            ByVal last As Integer, 
                            ByVal visit As Boolean(), 
      ByVal sum As Integer, ByVal length As Integer)
        if (start >= Me.size OrElse last >= Me.size OrElse 
            start < 0 OrElse last < 0 OrElse Me.size <= 0) Then
            Return
        End If
        if (visit(start) = True) Then
            '  Here length are indicate loop length
            if (length > 2 AndAlso start = last AndAlso sum < Me.result) Then
                '  Here length is indicate number of nodes
                '  Because graph is undirected so we consider all cycle 
                '  Which contains more than 2 node
                '  ---------------------
                '  When find a new min weight cycle
                Me.result = sum
            End If
            Return
        End If
        '  Here modified  the value of visited node
        visit(start) = True
        '  This is used to iterate nodes edges
        Dim edge As AjlistNode = Me.node(start).[next]
        while (edge IsNot Nothing)
            '   Find solution using recursion
            Me.minimumCycle(edge.id, last, visit, 
                            sum + (edge.weight), length + 1)
            '  Visit to next edge
            edge = edge.[next]
        End While
        '  Reset the value of visited node status
        visit(start) = False
    End Sub
    Public Sub minWeightCycle()
        if (Me.size <= 0) Then
            '  Empty graph
            Return
        End If
        '  Auxiliary space which is used to store 
        '  information about visited node
        '  Set initial visited node status 
        Dim visit As Boolean() = New Boolean(Me.size){}
        Me.result = Integer.MaxValue
        Dim i As Integer = 0
        While i < Me.size
            '  Check cycle of node i to i
            '  Here initial cycle weight is zero
            Me.minimumCycle(i, i, visit, 0, 0)
        i += 1
        End While
        '  Display result
        Console.WriteLine( vbLf &"Min weight cycle : " + Me.result.ToString())
    End Sub
    Public Shared Sub Main(ByVal args As String())
        '  6 implies the number of nodes in graph
        Dim g As Graph = New Graph(6)
        '  Connect node with an edge
        '  First and second parameter indicate node
        '  Last parameter is indicate weight
        g.addEdge(0, 1, 3)
        g.addEdge(0, 3, -3)
        g.addEdge(0, 4, 7)
        g.addEdge(0, 5, 1)
        g.addEdge(1, 2, 11)
        g.addEdge(1, 4, 8)
        g.addEdge(2, 3, 1)
        g.addEdge(2, 5, 4)
        g.addEdge(3, 4, 2)
        g.addEdge(4, 5, 8)
        g.addEdge(5, 1, 0)
        '  Print graph element
        g.printGraph()
        '  Test
        g.minWeightCycle()
    End Sub
End Class

Output

Adjacency list of vertex 0 :  1[3]  3[-3]  4[7]  5[1]
Adjacency list of vertex 1 :  0[3]  2[11]  4[8]  5[0]
Adjacency list of vertex 2 :  1[11]  3[1]  5[4]
Adjacency list of vertex 3 :  0[-3]  2[1]  4[2]
Adjacency list of vertex 4 :  0[7]  1[8]  3[2]  5[8]
Adjacency list of vertex 5 :  0[1]  2[4]  4[8]  1[0]
Min weight cycle : 3