Developer Assignment

DeveloperAssignment.vb

'   Bruno Galvao 
'   11/12/11
'
'    Given an array of integers between 1 and 1,000,000. 
'    One integer is in the array twice. Find the duplicate.

Module Module1

    Sub Main()

        Dim Numbers() As Integer = {5, 10, 12, 8, 8, 14}

        ' Unit Test
        ' Pass array as argument.
        Console.WriteLine(findDup(Numbers))

    End Sub

    Function findDup(ByVal Numbers() As Integer) As Integer

        Dim hash As HashSet(Of Integer)

        For Each Num In Numbers

            ' HashSet only accepts unique values
            ' If we try to add a duplicate value
            ' then hash.Add(Num) will fail.
            ' The returned value will be the duplicate.

            If (Not hash.Add(Num)) Then
                Return (Num)
            End If

        Next

        ' No duplicate found.
        Return (0)

    End Function

End Module

'   Bruno Galvao 
'   11/12/11
'
'    Find the first non-repeating character in a string:("DEFD" -> E )

Module Module2

    Sub Main()
        ' Unit test
        ' Pass string as argument.
        Console.WriteLine(nonRepeat("(""DEFD"" -> E )"))

    End Sub

    Function nonRepeat(ByVal aString As String) As String

        Dim repeated As Integer = 0

        For i = 0 To aString.Length - 1

            repeated = 0

            For j = 0 To aString.Length - 1

                ' If inner and outer For loops are on the same index then
                ' inner For loop moves to next index and compares character 
                ' with outer For loop character.
                ' If characters are equal then set repeated = 1 and Exit inner For loop.
                ' Otherwise, continue to find repeating character
                ' If reached end of string without finding repeating character
                ' then non-repeating character has been found and is returned.

                If ((i <> j) AndAlso (aString(i) = aString(j))) Then

                    ' Found repeating character 
                    repeated = 1

                    Exit For

                End If

            Next

            If (repeated = 0) Then

                ' Found first non-repeating character
                Return aString(i)

            End If
        Next

        Return ("No Non-Reapeating character!")

    End Function

End Module

'   Bruno Galvao 
'   11/12/11
'
'    A standard deck of 52 cards is represented in an array. 
'    Each card is represented as an integer. 
'    Write a method to shuffle the cards.

Module Module3

    Sub Main()

        ' Create deck of cards
        Dim Cards(51) As Integer

        ' Unit Test
        ' Pass array as argument.
        Console.WriteLine(shuffle(Cards))

    End Sub

    Function shuffle(ByVal Cards() As Integer)

        Dim rand = New Random()

        For counter = 0 To Cards.Length - 1

            Dim n = rand.Next(counter + 1)

            ' Swap card with random card in deck
            Dim temp = Cards(counter)
            Cards(counter) = Cards(n)
            Cards(n) = temp

        Next


        Return (Cards)

    End Function

End Module