' Einfache Umssetzung von ROT13 und ROT47

Function Rot13(s As String) As String
	Dim i As Integer, h As String, h2 As String
	
	h2 = ""
	For i = 1 To Len(s)
		h = Mid(s, i, 1)
		If h >= "A" And h <= "Z" Then
			h2 += Chr(Asc("A") + (Asc(h) + 13 - Asc("A")) Mod 26)
		ElseIf h >= "a" And h <= "z" Then
			h2 += Chr(Asc("a") + (Asc(h) + 13 - Asc("a")) Mod 26)
		Else
			h2 += h
		EndIf
	Next i
	Rot13 = h2
End Function

Function Rot47(s As String) As String
	Dim i As Integer, h As String, h2 As String
	
	h2 = ""
	For i = 1 To Len(s)
		h = Mid(s, i, 1)
		If h >= "!" And h <= "~" Then
			h2 += Chr(Asc("!") + (Asc(h) + 47 - Asc("!")) Mod 94)
		Else
			h2 += h
		EndIf
	Next i
	Rot47 = h2
End Function

Dim eing As String, eingRot13 As String, eingRot47 As String

ScreenRes 640, 480, 4
Width 80, 30

Line Input !"Zu \"verschl\129sselnder\" Text:", eing

eingRot13 = Rot13(eing)
eingRot47 = Rot47(eing)
Print "Rot13-Chiffrat: "; eingRot13
Print "Rot47-Chiffrat: "; eingRot47
Print !"ROT13 zur\129ckgerechnet: "; Rot13(eingRot13)
Print !"ROT47 zur\129ckgerechnet: "; Rot47(eingRot47)

Sleep