#define isNumeric(ch) (ch >= "0" And ch <= "9")

Type Rueda
    nombre As String * 1  ' Fixed-length string for better performance
    valor As String
    index As Integer
End Type

Function Girar(Byref wheel As Rueda, dato() As Rueda) As String
    wheel.index = (wheel.index + 1) Mod Len(wheel.valor)
    Dim As String c = Mid(wheel.valor, wheel.index + 1, 1)

    If IsNumeric(c) Then Return c

    For i As Integer = 0 To Ubound(dato)
        If dato(i).nombre = c Then  Return Girar(dato(i), dato())
    Next

    Return ""
End Function

Function GirarRuedas(wheels() As Rueda) As String Static
    Static As String result
    Static As Integer cnt, maxCnt = 20
    Static dato() As Rueda

    result = ""
    Redim dato(Ubound(wheels))

    For i As Integer = 0 To Ubound(wheels)
        dato(i) = wheels(i)
        dato(i).index = -1  'Initialize to -1 so first increment gives 0
    Next i

    For cnt = 0 To maxCnt - 1
        result &= Girar(dato(0), dato())
    Next

    Return result
End Function

Sub Mostrar(Byref secuencia As String)
    For i As Integer = 1 To Len(secuencia)
        Print Mid(secuencia, i, 1);
        If i < Len(secuencia) Then Print " ";
    Next i
    Print "..."
End Sub

' Test cases initialization helper
Sub InitWheel(Byref w As Rueda, n As String, v As String)
    w.nombre = n
    w.valor = v
    w.index = 0
End Sub

' Main program
Print "Intersecting Number Wheel group:"

' First test case
Dim wheels1(0) As Rueda
InitWheel(wheels1(0), "A", "123")
Print "  A: [1 2 3]"
Print "  Generates:"
Print "    ";
Mostrar GirarRuedas(wheels1())

Print !"\nIntersecting Number Wheel group:"
' Second test case
Dim wheels2(1) As Rueda
InitWheel(wheels2(0), "A", "1B2")
InitWheel(wheels2(1), "B", "34")
Print "  A: [1 B 2]"
Print "  B: [3 4]"
Print "  Generates:"
Print "    ";
Mostrar GirarRuedas(wheels2())

Print !"\nIntersecting Number Wheel group:"
' Third test case
Dim wheels3(1) As Rueda
InitWheel(wheels3(0), "A", "1DD")
InitWheel(wheels3(1), "D", "678")
Print "  A: [1 D D]"
Print "  D: [6 7 8]"
Print "  Generates:"
Print "    ";
Mostrar GirarRuedas(wheels3())

Print !"\nIntersecting Number Wheel group:"
' Fourth test case
Dim wheels4(2) As Rueda
InitWheel(wheels4(0), "A", "1BC")
InitWheel(wheels4(1), "B", "34")
InitWheel(wheels4(2), "C", "5B")
Print "  A: [1 B C]"
Print "  B: [3 4]"
Print "  C: [5 B]"
Print "  Generates:"
Print "    ";
Mostrar GirarRuedas(wheels4())

Sleep