' Evil number = positive whole number whose binary representation contains an even number of 1's
Imports System
Public Class Program
Public Shared Function countNumberOfOne(ByVal binaryNumber As String) As Integer
Dim length As Integer = binaryNumber.Length
Dim count As Integer = 0
Dim ch As Char
For i As Integer = 0 To length - 1
ch = binaryNumber(i)
If ch = "1"c Then
count += 1
End If
Next
Return count
End Function
Public Shared Function checkEvilNumber(ByVal number As Integer) As Boolean
Dim binaryNumber As String = Convert.ToString(number, 2)
Console.Write(number & " = " & binaryNumber & " = ")
Return If ((countNumberOfOne(binaryNumber) Mod 2 = 0), True, False)
End Function
Public Shared Sub Main(ByVal args As String())
Dim number As Integer = 23
Console.WriteLine(checkEvilNumber(number))
number = 9863
Console.WriteLine(checkEvilNumber(number))
End Sub
End Class
' run:
'
' 23 = 10111 = True
' 9863 = 10011010000111 = False
'
