Public Class Form1
    Private j As Integer
    Private rn As Integer

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        txt_nr_of_filled_books.BackColor = Color.OrangeRed
        txt_percent_filled.BackColor = Color.OrangeRed
        txt_nr_of_filled_books.Refresh()
        txt_percent_filled.Refresh()

        Dim i As Integer
        Dim j As Integer
        Dim q As Integer
        Dim r As Double

        Dim k As Integer 'Anzahl der Sammler
        k = CInt(txt_nr_of_collectors.Text)

        Dim o As Integer 'Anzahl der Sammelbilder
        o = CInt(txt_nr_of_items.Text)

        Dim p As Integer 'Anzahl der gekauften Sammelbilder
        p = CInt(txt_nr_of_coupons.Text)

        Do
            Dim arr(o) As Integer 'Hier werden die "Sammelbilder" eingeklebt

            For i = 1 To p
                rn = CInt(Int((o * Rnd()) + 1)) 'zufällig ein Sammelbild zwischen 1 und o auswählen
                arr(rn) = arr(rn) + 1 'Bild einkleben
            Next
            Array.Sort(arr) 'arr sortieren nach "Bildanzahl" je Position
            If arr(1) > 0 Then q = q + 1 'falls das Album voll ist ist die Position 1 ungleich Null
            j = j + 1

            txt_nr_of_filled_books.Text = CStr(q)
            txt_nr_of_filled_books.Refresh()

            r = (q / k) * 100

            txt_percent_filled.Text = CStr(r)
            txt_percent_filled.Refresh()
        Loop While j < k
        txt_nr_of_filled_books.BackColor = Color.White
        txt_percent_filled.BackColor = Color.White
    End Sub
   
End Class