Imports System
Module PowerOfTwoCheck
' Method A: Bit-counting (similar to your Python example)
Function IsPowerOfTwoA(x As Integer) As Boolean
If x <= 0 Then Return False
Return System.Numerics.BitOperations.PopCount(CUInt(x)) = 1
End Function
' Method B: Bitwise trick
Function IsPowerOfTwoB(x As Integer) As Boolean
Return x > 0 AndAlso (x And (x - 1)) = 0
End Function
' Method C: Repeated division
Function IsPowerOfTwoC(x As Integer) As Boolean
If x <= 0 Then Return False
While x Mod 2 = 0
x \= 2
End While
Return x = 1
End Function
' Method D: Using logarithms
Function IsPowerOfTwoD(x As Integer) As Boolean
If x <= 0 Then Return False
Dim logVal As Double = Math.Log(x) / Math.Log(2)
Return Math.Abs(logVal - Math.Round(logVal)) < 1.0E-10
End Function
Sub Main()
Dim test1 As Integer = 16 ' true
Dim test2 As Integer = 18 ' false
Console.WriteLine("A: " & IsPowerOfTwoA(test1) & ", " & IsPowerOfTwoA(test2))
Console.WriteLine("B: " & IsPowerOfTwoB(test1) & ", " & IsPowerOfTwoB(test2))
Console.WriteLine("C: " & IsPowerOfTwoC(test1) & ", " & IsPowerOfTwoC(test2))
Console.WriteLine("D: " & IsPowerOfTwoD(test1) & ", " & IsPowerOfTwoD(test2))
End Sub
End Module
' OUTPUT:
'
' A: True, False
' B: True, False
' C: True, False
' D: True, False
'
