Module Module1

    Sub Main()
        Dim a() As Single, b() As Single, c() As Single
        Dim n As Integer
        n = InputBox("Введите n")
        ReDim a(n)
        ReDim b(n)
        ReDim c(n)
        InputVector(a, "a")
        InputVector(b, "b")
        InputVector(c, "c")
        MsgBox("Одинаковых между A, B: " + CheckVectors(a, b).ToString)
        MsgBox("Одинаковых между B, C: " + CheckVectors(b, c).ToString)
    End Sub
    Private Sub InputVector(ByRef x() As Single, Optional ByVal ArrayName As String = "элемент")
        Dim i As Integer
        For i = 1 To x.GetUpperBound(0)
            x(i) = InputBox(ArrayName & "(" & i & ") = ?")
        Next
    End Sub
    Function CheckVectors(ByRef x() As Single, ByRef y() As Single) As Integer
        Dim i As Integer, result As Integer
        result = 0
        For i = 0 To x.GetUpperBound(0) - 1
            If (x(i) = y(i)) Then
                result = result + 1
            End If
        Next i
        Return result
    End Function
End Module