VBA 两列去重并提取不重复数据到新列

Sub CheckDiff()

    Dim r%, i%

    Dim arr, brr

    Dim d As Object

    Set d = CreateObject("scripting.dictionary")

    With Worksheets("sheetName")

        r = .Cells(.Rows.Count, 1).End(xlUp).Row

        arr = .Range("a2:a" & r)

        For i = 1 To UBound(arr)

          d(arr(i, 1)) = ""

        Next

        r = .Cells(.Rows.Count, 2).End(xlUp).Row

        arr = .Range("b2:b" & r)

        ReDim brr(1 To UBound(arr), 1 To 1)

        m = 0

        For i = 1 To UBound(arr)

          If Not d.exists(arr(i, 1)) Then

            m = m + 1

            brr(m, 1) = arr(i, 1)

          End If

        Next

        .Range("c2").Resize(m, 1) = brr

    End With

End Sub