BFS

   OpenFileDialog1.Filter = "文字檔案(*.txt)|*.txt"
        Label1.Text = "" : Label2.Text = "" : Label3.Text = "" : Label4.Text = ""
        Dim txtname As String = ""
        If OpenFileDialog1.ShowDialog = DialogResult.OK Then txtname = My.Computer.FileSystem.ReadAllText(OpenFileDialog1.FileName)
        Label4.Text = OpenFileDialog1.SafeFileName
        Label1.Text = txtname
        Dim Map(8, 8), Cinx(2, 8, 8), count As Integer : Dim Memory(8, 8) As Boolean
        Dim Maze As String = Replace(Replace(txtname, Chr(13), ""), Chr(10), "")
        For i = 1 To 8 '讀取與重置
            For j = 1 To 8
                Memory(i, j) = True
                count += 1 : Map(i, j) = Mid(Maze, count, 1)
                If Mid(Maze, count, 1) = "1" Then Memory(i, j) = False
            Next
        Next
        Dim qx, qy As String : qx = 1 : qy = 1 'Stack
        Dim dx() As Integer = {0, -1, 0, 1} : Dim dy() As Integer = {-1, 0, 1, 0} '移動方向
        Cinx(0, 0, 0) = 0 : Cinx(1, 0, 0) = 0
        Dim nx, ny, MIDcount, Bug As Integer : nx = 1 : ny = 1
        Do While Len(qx) <> 0 And Len(qy) <> 0 'BFS
            MIDcount += 1 : Bug += 1
            nx = Val(Mid(qx, MIDcount, 1)) : ny = Val(Mid(qy, MIDcount, 1))
            If nx = 8 And ny = 8 Then Exit Do
            For i = 0 To 3
                If nx + dx(i) <= 8 And nx + dx(i) >= 1 And ny + dy(i) <= 8 And ny + dy(i) >= 1 Then
                    If Memory(nx + dx(i), ny + dy(i)) = True Then
                        qx = qx & (nx + dx(i)) : qy = qy & (ny + dy(i))
                        Memory(nx, ny) = False
                        Cinx(0, nx + dx(i), ny + dy(i)) = nx
                        Cinx(1, nx + dx(i), ny + dy(i)) = ny
                    End If
                End If
            Next
            If Bug > 100 Then Label2.Text = "No way" : Exit Sub
        Loop
        Dim x, y, fx, fy As Integer : x = 8 : y = 8
        Dim NewMap(8, 8), MazeStep As Integer
        For i = 1 To 8
            For j = 1 To 8
                NewMap(i, j) = 0
            Next
        Next
        NewMap(8, 8) = 5
        Do While x <> -1 And y <> -1
            fx = Cinx(0, x, y) : fy = Cinx(1, x, y)
            x = fx : y = fy : MazeStep += 1
            NewMap(x, y) = 5
            If x = 0 And y = 0 Then Exit Do
        Loop
        For i = 1 To 8
            For j = 1 To 8
                Label2.Text &= NewMap(i, j)
            Next
            Label2.Text &= vbNewLine
        Next
        Label3.Text = "step" & MazeStep - 1