How to transpose duplicated data in rows into columns

I currently trying to clean up a large dataset using Excel VBA. The dataset structure looks like this.

However, I would like to make it look like this instead, whereby if the cells in columns A:D all contain the same value, transpose the cells in column E. (And remove the duplicated cells from A:D)

Here is the code I did

Dim ws As Worksheet: Set ws = Sheets("test")
lastrow = ws.Cells(ws.Rows.Count, "A").End(xlUp).Row

Dim j As Integer
j = 6

For i = 2 To lastrow

    If (Range("A" & i).Value = Range("A" & i + 1).Value) And (Range("B" & i).Value = Range("B" & i + 1).Value) And (Range("C" & i).Value = Range("C" & i + 1).Value) Then
        Cells(i, j).Value = Cells(i + 1, 5).Value
        j = j + 1
    End If
    
    'Reset J back to 6 if columns A to D does not match previous
    If (Range("A" & i).Value <> Range("A" & i + 1).Value) Or (Range("B" & i).Value <> Range("B" & i + 1).Value) Or (Range("C" & i).Value <> Range("C" & i + 1).Value) Then
        j = 6
    End If
    
Next i

How can this be done?

Solution

This ended up more complex than I'd thought but seems to work OK

Sub Compact()

    Const KEY_COLS As Long = 4
    Dim ws As Worksheet, i As Long, k As String, nextEmpty As Long
    Dim dict As Object
    Set dict = CreateObject("scripting.dictionary")
    
    Set ws = Sheets("test")
    For i = 1 To ws.Cells(ws.Rows.Count, "A").End(xlUp).Row
        'create a row "key" from first KEY_COLS cells
        k = Join(Application.Transpose(Application.Transpose( _
                  ws.Cells(i, 1).Resize(1, KEY_COLS))), "~~")
        
        If Not dict.exists(k) Then
            'move this row up?
            If nextEmpty > 0 Then
                ws.Cells(i, 1).Resize(1, KEY_COLS + 1).Cut ws.Cells(nextEmpty, 1)
                dict.Add k, nextEmpty 'new key - store row#
                nextEmpty = 0
            Else
                dict.Add k, i 'new key - store row#
            End If
        Else
            'seen this key before - move value to that row and clear
            ws.Cells(dict(k), Columns.Count).End(xlToLeft).Offset(0, 1).Value = _
                ws.Cells(i, KEY_COLS + 1).Value
            ws.Rows(i).ClearContents
            If nextEmpty = 0 Then nextEmpty = i 'available row
        End If
    Next i
End Sub

Edit: this is a bit cleaner I think. It's split into separate "read" and "write" parts.

Sub Compact2()

    Const KEY_COLS As Long = 4
    Const SEP As String = "~~"
    Dim ws As Worksheet, i As Long, k, col As Long, v
    Dim dict As Object
    Set dict = CreateObject("scripting.dictionary")
    
    Set ws = Sheets("test")
    'collect all the unique combinations and associated values 
    For i = 1 To ws.Cells(ws.Rows.Count, "A").End(xlUp).Row
        'create a row "key" from first KEY_COLS cells
        k = Join(Application.Transpose(Application.Transpose( _
                  ws.Cells(i, 1).Resize(1, KEY_COLS))), SEP)
        
        If Not dict.exists(k) Then dict.Add k, New Collection
        dict(k).Add ws.Cells(i, KEY_COLS + 1).Value
        ws.Rows(i).ClearContents 'clear row
    Next i
    
    're-populate the sheet from the dictionary
    i = 1
    For Each k In dict
        ws.Cells(i, 1).Resize(1, KEY_COLS).Value = Split(k, SEP)
        col = KEY_COLS + 1
        For Each v In dict(k)
            ws.Cells(i, col) = v
            col = col + 1
        Next v
        i = i + 1
    Next k
End Sub