VERSION 5.00
Begin VB.Form frmOSPF 
   Caption         =   "最短路徑選擇"
   ClientHeight    =   4650
   ClientLeft      =   3360
   ClientTop       =   2910
   ClientWidth     =   7170
   Icon            =   "OSPF.frx":0000
   LinkTopic       =   "Form2"
   LockControls    =   -1  'True
   ScaleHeight     =   4650
   ScaleWidth      =   7170
   Begin VB.TextBox Text1 
      Height          =   3375
      Left            =   240
      MultiLine       =   -1  'True
      ScrollBars      =   2  'Vertical
      TabIndex        =   5
      Top             =   1080
      Width           =   6735
   End
   Begin VB.CommandButton Command1 
      Caption         =   "打印最短路線"
      Height          =   495
      Left            =   4320
      TabIndex        =   4
      Top             =   360
      Width           =   2055
   End
   Begin VB.ComboBox Combo2 
      Height          =   300
      Left            =   1680
      TabIndex        =   2
      Text            =   "終點站"
      Top             =   600
      Width           =   1215
   End
   Begin VB.ComboBox Combo1 
      Height          =   300
      Left            =   240
      TabIndex        =   1
      Text            =   "起訖站"
      Top             =   600
      Width           =   1215
   End
   Begin VB.Label Label2 
      AutoSize        =   -1  'True
      Caption         =   "終點站："
      Height          =   180
      Left            =   1800
      TabIndex        =   3
      Top             =   240
      Width           =   720
   End
   Begin VB.Label Label1 
      AutoSize        =   -1  'True
      Caption         =   "起訖站："
      Height          =   180
      Left            =   240
      TabIndex        =   0
      Top             =   240
      Width           =   720
   End
End
Attribute VB_Name = "frmOSPF"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Dim start, ends As Long
Dim JLH(1 To 300), LJD(1 To 300, 1 To 4), DST(1 To 300, 1 To 4) As Long
Dim BH(1 To 300), ADD(1 To 300) As String
Dim n As Integer
Dim vertexnum As Integer
Dim edgenum As Integer
Const max = 100000
Dim graph(0 To 300, 0 To 300) As Long
Dim visited(0 To 300) As Integer
Dim path(0 To 300) As Integer
Dim distance(0 To 90000) As Long

Private Function dijkstra(begin As Integer)
    Dim minedge, vertex, i, j, n, m, edges As Integer
    edges = 1
    visited(begin) = 1
    For i = 1 To vertexnum
        distance(i) = graph(begin, i)
'        Debug.Print distance(i)
    Next i
        distance(begin) = 0
              While (edges < vertexnum - 1)
                edges = edges + 1
                minedge = max
                For j = 1 To vertexnum
                    If visited(j) = 0 And minedge > distance(j) Then
                        vertex = j
                        minedge = distance(j)
                    End If
                Next j
                visited(vertex) = 1
                For n = 1 To vertexnum
                    If visited(n) = 0 And (distance(vertex) + graph(vertex, n)) < distance(n) Then
                        distance(n) = distance(vertex) + graph(vertex, n)
                        path(n) = vertex
                    End If
                Next
              Wend
End Function
Private Sub Command1_Click()
    Dim i, j As Integer
    Dim k As Integer
    Dim addname(1 To 100) As String
    
    Text1 = ""
        If start = 0 Or ends = 0 Then
        MsgBox "請選擇起始站與終點站"
        Exit Sub
    End If
    For i = 1 To vertexnum
        visited(i) = 0
        path(i) = 1
    Next
    dijkstra (start)
    Text1 = "起訖站：" & ADD(start) & "  -->  " & "終點站：" & ADD(ends) & vbCrLf
    Text1 = Text1 & vbCrLf
    If distance(ends) = max Then
        Text1 = Text1 & "兩站點間沒有可聯接的路線！"
        Exit Sub
    Else
        Text1 = Text1 & "它們之間的距離為： " & distance(ends) * 0.1 & "  Km" & vbCrLf
        Text1 = Text1 & vbCrLf
        Text1 = Text1 & "它們之間的最短路線為：" & vbCrLf
        Text1 = Text1 & vbCrLf
        Text1 = Text1 & ADD(start)
    End If
    k = ends
    j = 1
    Do
        addname(j) = ADD(k)
        k = path(k)
        j = j + 1
    Loop While (k <> 1)
    For j = j - 1 To 1 Step -1
        Text1 = Text1 & "--> " & addname(j)
    Next j
End Sub

Private Sub Form_Initialize()
    Dim i, j, k As Long
    Dim filename As String
    Dim buffers As String
    
    On Error Resume Next
    
    filename = App.path + "\" + "Add_Dst" + ".txt"
    Open filename For Input As #1
    If LOF(1) = 0 Then
        MsgBox "The lenth of the file is zero! Please Select it asgain。" & vbCrLf & "The file name is Add_Dst。"
        
        Exit Sub
    End If
    i = 1
    Do While Not EOF(1)
    Line Input #1, buffers
        BH(i) = Val(Mid$(buffers, 1, 3))
        ADD(i) = Mid$(buffers, 4, 4)
            Combo1.AddItem ADD(i)
            Combo2.AddItem ADD(i)
        LJD(i, 1) = Val(Mid$(buffers, 8, 3))    '鄰接點的編號
        DST(i, 1) = Val(Mid$(buffers, 11, 2))    '與鄰接點之間的距離
        LJD(i, 2) = Val(Mid$(buffers, 13, 3))
        DST(i, 2) = Val(Mid$(buffers, 16, 2))
        LJD(i, 3) = Val(Mid$(buffers, 18, 3))
        DST(i, 3) = Val(Mid$(buffers, 21, 2))
        LJD(i, 4) = Val(Mid$(buffers, 24, 3))
        DST(i, 4) = Val(Mid$(buffers, 27, 2))
        Kill buffers
        i = i + 1
    Loop
        n = i - 1
'       Debug.Print n
    Close #1
       
    vertexnum = n  '設置圖的頂點數
    
    edgenum = 0
   
    For i = 1 To n
        For j = 1 To 4
            If LJD(i, j) = 0 Then Exit For
            edgenum = edgenum + 1    '獲得圖的邊數
            graph(i, LJD(i, j)) = DST(i, j)   '從i點與其鄰接點LJD(i,j)的距離
        Next
    Next

    For i = 0 To n
        For j = 0 To n
            If graph(i, j) = 0 Then
                graph(i, j) = max
            End If
        Next
    Next
End Sub
Private Sub Combo1_click()
    start = Combo1.ListIndex + 1      '獲得起訖站的編號
End Sub

Private Sub Combo2_click()
    ends = Combo2.ListIndex + 1      '獲得終點站的編號
End Sub