RosettaCodeData/Task/Population-count/Visual-Basic-.NET/population-count.vb

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1.6 KiB
VB.net
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Imports System.Console, System.Diagnostics
Module Module1
Dim i As Integer, eo As Boolean
 
Function PopCnt(n As Long) As Integer
Return Convert.ToString(n, 2).ToCharArray().Where(Function(x) x = "1").Count()
End Function
 
Sub Aline(a As List(Of Integer), title As String)
WriteLine("{0,-8}{1}", title, String.Join(" ", a.Take(30)))
End Sub
Sub Main(ByVal args As String())
WriteLine("Population Counts:") : Dim t, e, o As New List(Of Integer)
For c As Integer = 0 To 99
If (PopCnt(c) And 1) = 0 Then e.Add(c) Else o.Add(c)
If c < 30 Then t.Add(PopCnt(CLng(Math.Pow(3, c))))
Next
Aline(t, "3^n :") : Aline(e, "Evil:") : Aline(o, "Odious:")
' Extra:
WriteLine(vbLf & "Pattern:{0}", Pattern(e, o))
If Debugger.IsAttached Then ReadKey()
End Sub
' support routines for pattern output
Function Same(a As List(Of Integer)) As Boolean
Return a(i) + 1 = a(i + 1)
End Function
Function Odd(a As List (Of Integer), b As List (Of Integer)) As Boolean
eo = Not eo : If a(i) = b(i) + 1 Then i -= 1 : Return True
Return False
End Function
Function SoO(a As List (Of Integer), b As List (Of Integer), c As String) As String
Return If(Same(a), c(0), If(Odd(b, a), c(1), c(2)))
End Function
Function Either(a As List(Of Integer), b As List(Of Integer)) As String
Return If(eo, SoO(a, b, "⌢↓↘"), SoO(b, a, "⌣↑↗"))
End Function
Function Pattern(a As List(Of Integer), b As List(Of Integer)) As String
eo = a.Contains(0) : Dim res As New Text.StringBuilder
For i = 0 To a.Count - 2 : res.Append(Either(a, b)) : Next
Return res.ToString()
End Function
End Module