Module Recursion

    Sub main()

        Console.WriteLine("1 for binary 2 for factorial")

        Dim ans As Char = Console.ReadLine()

        Console.WriteLine("Enter Number")

        Dim num As Integer = Console.ReadLine()

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        Dim resul As Integer = 0

        If ans = "2" Then

            resul = factorial(num)

            Console.Write(resul)

        ElseIf ans = "1" Then

            S(num)

        End If

        Console.ReadLine()

    End Sub

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    Function factorial(num As Integer)

        Dim result As Integer = 1

        If num = 0 Then

            Return 1

        Else

            Return num * factorial(num - 1)

        End If

    End Function

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    Function S(ByVal num As Integer)

        If num = 1 Or num = 0 Then

            Console.Write(num)

        Else

            S(num / 2)

            Console.Write(num Mod 2)

        End If

    End Function

End Module

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