Negative base numbers: Difference between revisions
→{{header|VBA}}
Line 1,647:
</pre>
=={{header|VBA}}==
{{trans|Modula-2}}
<lang vb>Const DIGITS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
Dim Str(63) As String
Private Function mod2(a As Long, b As Integer) As Long
mod2 = a - (a \ b) * b
End Function
Private Function swap(a As String, b As String)
Dim t As String
t = a
a = b
b = t
End Function
Private Function EncodeNegativeBase(ByVal n As Long, base As Integer) As String
Dim ptr, idx As Long
Dim rem_ As Long
Dim result As String
If base > -1 Or base < -62 Then
EncodeNegativeBase = result
Else
If n = 0 Then
EncodeNegativeBase = "0"
Else
ptr = 0
Do While n <> 0
rem_ = mod2(n, base)
n = n \ base
If rem_ < 0 Then
n = n + 1
rem_ = rem_ - base
End If
result = result & Mid(DIGITS, rem_ + 1, 1)
Loop
End If
End If
EncodeNegativeBase = StrReverse(result)
End Function
Private Function DecodeNegativeBase(ns As String, base As Integer) As Long
Dim total As Long, bb As Long
Dim i As Integer, j As Integer
If base < -62 Or base > -1 Then DecodeNegativeBase = 0
If Mid(ns, 1, 1) = 0 Or (Mid(ns, 1, 1) = "0" And Mid(ns, 2, 1) = 0) Then DecodeNegativeBase = 0
i = Len(ns)
total = 0
bb = 1
Do While i >= 1
j = InStr(1, DIGITS, Mid(ns, i, 1), vbTextCompare) - 1
total = total + j * bb
bb = bb * base
i = i - 1
Loop
DecodeNegativeBase = total
End Function
Private Sub Driver(n As Long, b As Integer)
Dim ns As String
Dim p As Long
ns = EncodeNegativeBase(n, b)
Debug.Print CStr(n); " encoded in base "; b; " = "; ns
p = DecodeNegativeBase(ns, b)
Debug.Print ns; " decoded in base "; b; " = "; p
Debug.Print
End Sub
Public Sub main()
Driver 10, -2
Driver 146, -3
Driver 15, -10
Driver 118492, -62
End Sub</lang>
{{out}}
<pre>10 encoded in base -2 = 11110
11110 decoded in base -2 = 10
146 encoded in base -3 = 21102
21102 decoded in base -3 = 146
15 encoded in base -10 = 195
195 decoded in base -10 = 15
118492 encoded in base -62 = VBA
VBA decoded in base -62 = 118492 </pre>
=={{header|zkl}}==
<lang zkl>fcn toNBase(n,radix){
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