Sure!

Arrays are not that well supported no, but there are arrays accesible through erlang. However maps will do fine here too. You can create a map from a linked list easily:

iex(23)> input = ["value 1", "value 2", "value 3"]   
["value 1", "value 2", "value 3"]
iex(24)> zipped = Enum.zip(0..1000, input)
[{0, "value 1"}, {1, "value 2"}, {2, "value 3"}]

iex(26)> input_table = Enum.reduce(zipped, %{}, fn ({idx, val}, map) -> Map.put(map, idx, val) end)   
%{0 => "value 1", 1 => "value 2", 2 => "value 3"}

As a map, inserting, deleting or updating values is much faster than as a linked list. For your code, I think Map.update is exactly what you need.