' vbc /removeintchecks+
' dotnet build -p:RemoveIntegerChecks=True
Imports System

' 線形合同法による疑似乱数の生成を実装したクラス
Class LCGRandom
  Inherits Random

  Private x As Long
  Private Const a As Long = 1140671485
  Private Const c As Long = 12820163

  Public Sub New()
    Me.New(Environment.TickCount) ' Environment.TickCountの値をデフォルトのシード値として使用する
  End Sub

  Public Sub New(ByVal seed As Integer)
    x = seed
  End Sub

  Protected Overrides Function Sample() As Double
    x = (a * x + c) And Long.MaxValue

    Return CDbl(x) / Long.MaxValue
  End Function
End Class

Class Sample
  Shared Sub Main()
    Dim rand As New Random(0)
    Dim lcg As New LCGRandom(0)

    Const format As String = "{0,-6} {1,-6}"

    Console.WriteLine(
      format,
      NameOf(rand),
      NameOf(lcg)
    )

    For i As Integer = 1 To 15
      Console.WriteLine(
        format,
        rand.Next(0, 100),
        lcg.Next(0, 100)
      )
    Next
  End Sub
End Class

rand   lcg   
72     0     
81     0     
76     97    
55     2     
20     65    
55     93    
90     23    
44     65    
97     44    
27     61    
29     37    
46     18    
63     78    
46     82    
98     28