Const NULL As Any Ptr = 0

Type item_t
    As String nombre
    As Integer Ptr deps
    As Integer n_deps
    As Integer  idx
    As Integer depth
End Type

Dim Shared As String entrada
entrada = "des_system_lib   std synopsys std_cell_lib des_system_lib dw02 dw01 ramlib ieee" & Chr(10) & _
"dw01             ieee dw01 dware gtech" & Chr(10) & _
"dw02             ieee dw02 dware" & Chr(10) & _
"dw03             std synopsys dware dw03 dw02 dw01 ieee gtech" & Chr(10) & _
"dw04             dw04 ieee dw01 dware gtech" & Chr(10) & _
"dw05             dw05 ieee dware" & Chr(10) & _
"dw06             dw06 ieee dware" & Chr(10) & _
"dw07             ieee dware" & Chr(10) & _
"dware            ieee dware" & Chr(10) & _
"gtech            ieee gtech" & Chr(10) & _
"ramlib           std ieee" & Chr(10) & _
"std_cell_lib     ieee std_cell_lib" & Chr(10) & _
"synopsys" & Chr(10) & _
"cycle_11         cycle_12" & Chr(10) & _
"cycle_12         cycle_11" & Chr(10) & _
"cycle_21         dw01 cycle_22 dw02 dw03" & Chr(10) & _
"cycle_22         cycle_21 dw01 dw04" & Chr(10)

Function get_item(list() As item_t, Byref longi As Integer, nombre As String) As Integer
    Dim As Integer i
    For i = 0 To longi - 1
        If list(i).nombre = nombre Then Return i
    Next

    longi += 1
    Redim Preserve list(longi - 1)
    i = longi - 1
    list(i).idx = i
    list(i).nombre = nombre
    list(i).n_deps = 0
    list(i).deps = NULL
    list(i).depth = 0
    Return i
End Function

Sub add_dep(Byref it As item_t, i As Integer)
    If it.idx = i Then Return
    it.deps = Reallocate(it.deps, (it.n_deps + 1) * Sizeof(Integer))
    it.deps[it.n_deps] = i
    it.n_deps += 1
End Sub

Function parse_input(ret() As item_t) As Integer
    Dim As Integer i, parent, idx, n_items, posic, nextpos
    Dim As item_t list()
    Dim As String s, linea, word

    n_items = 0
    s = entrada

    Do While Len(s) > 0
        posic = Instr(s, Chr(10))
        If posic = 0 Then
            linea = s
            s = ""
        Else
            linea = Left(s, posic - 1)
            s = Mid(s, posic + 1)
        End If

        i = 0
        While Len(linea) > 0
            linea = Trim(linea)
            If Len(linea) = 0 Then Exit While

            posic = Instr(linea, " ")
            If posic = 0 Then
                word = linea
                linea = ""
            Else
                word = Left(linea, posic - 1)
                linea = Mid(linea, posic + 1)
            End If

            If Len(word) > 0 Then
                idx = get_item(list(), n_items, word)

                If i = 0 Then
                    parent = idx
                Else
                    add_dep(list(parent), idx)
                End If
                i += 1
            End If
        Wend
    Loop

    Redim ret(n_items - 1)
    For i = 0 To n_items - 1
        ret(i) = list(i)
    Next

    Return n_items
End Function

Function get_depth(base_() As item_t, idx As Integer, bad As Integer) As Integer
    Dim As Integer max = 1, i, t

    If base_(idx).n_deps = 0 Then
        base_(idx).depth = 1
        Return 1
    End If

    If base_(idx).depth < 0 Then Return base_(idx).depth
    If base_(idx).depth > 0 Then Return base_(idx).depth

    base_(idx).depth = bad
    For i = 0 To base_(idx).n_deps - 1
        t = get_depth(base_(), base_(idx).deps[i], bad)
        If t < 0 Then
            max = t
            Exit For
        End If
        If max < t + 1 Then max = t + 1
    Next

    base_(idx).depth = max
    Return max
End Function

' Main program
Dim As Integer i, j, n, bad = -1, max = -1000000, min = 1000000
Dim As item_t items()

n = parse_input(items())

For i = 0 To n - 1
    If items(i).depth = 0 And get_depth(items(), i, bad) < 0 Then bad -= 1
Next

For i = 0 To n - 1
    If items(i).depth > max Then max = items(i).depth
    If items(i).depth < min Then min = items(i).depth
Next

Print "Compile order:"
For i = min To max
    If i = 0 Then Continue For

    If i < 0 Then
        Print "   [unorderable]";
    Else
        Print i; ":";
    End If

    For j = 0 To n - 1
        If items(j).depth = i Then Print " "; items(j).nombre;
    Next
    Print
Next

' Clean up memory
For i = 0 To n - 1
    If items(i).deps <> NULL Then Deallocate(items(i).deps)
Next

Sleep