PHP - 重新排列多个数组，以便某些组合具有相同的键（索引）

Question

I have an array, which looks like this:

Array
(
[sku_0017768] => Array
    (
        [0] => 0f359ce5bf6dc855f160c9b89b4aada0
    )

[sku_0017766] => Array
    (
        [0] => ff5a47bd699bcb52944d0727a5b443b6
        [1] => 0f359ce5bf6dc855f160c9b89b4aada0
    )

[sku_0017723] => Array
    (
        [3] => a3c83832b4089d83d164b3cac596fc7e
    )

[sku_0017767] => Array
    (
        [0] => fb91d14d405be52ce989acd2918ea1a0
    )

[sku_8402350] => Array
    (
        [0] => a3c83832b4089d83d164b3cac596fc7e
        [1] => fb91d14d405be52ce989acd2918ea1a0
        [2] => ff5a47bd699bcb52944d0727a5b443b6
        [3] => d14afce16e477663ebe51fdd65cd5010
    )

[sku_8402200] => Array
    (
        [0] => d14afce16e477663ebe51fdd65cd5010
    )

)

Now, this array represents a list of SKU's with one or more 'combination codes'. So, in this example 'sku_0017768' matches product sku_0017766 because they share the same combination code.

sku_8402350 has multiple combination as you can see.

What I need to have now is a new array, where the index(key) of the combination code needs to be same among the other products within the combination.

Output should look like this:

Array
(
[sku_0017768] => Array
    (
       [0] => 0f359ce5bf6dc855f160c9b89b4aada0
    )

[sku_0017766] => Array
    (
       [0] => 0f359ce5bf6dc855f160c9b89b4aada0
       [1] => ff5a47bd699bcb52944d0727a5b443b6
    )

[sku_0017723] => Array
    (
       [0] => a3c83832b4089d83d164b3cac596fc7e
    )


[sku_0017767] => Array
    (
       [0] => fb91d14d405be52ce989acd2918ea1a0
    )

[sku_8402350] => Array
    (
       [0] => fb91d14d405be52ce989acd2918ea1a0
       [1] => ff5a47bd699bcb52944d0727a5b443b6
       [2] => d14afce16e477663ebe51fdd65cd5010
       [3] => a3c83832b4089d83d164b3cac596fc7e
    )

[sku_8402200] => Array
    (
       [2] => d14afce16e477663ebe51fdd65cd5010
    )
)

The difficulty I have is that when a key is already in use, the key of the other products within the combination should increase (with 1) as well, until there is an empty key which the combination can use.

Can anybody help me pointing me in the right direction? Feel free to ask if anything is not clear.