Data commit

Task/Best-shuffle/Erlang/best-shuffle.erl

@@ -0,0 +1,38 @@
+-module( best_shuffle ).
+
+-export( [sameness/2, string/1, task/0] ).
+
+sameness( String1, String2 ) -> lists:sum( [1 || {X, X} <- lists:zip(String1, String2)] ).
+
+string( String ) ->
+	{"", String, Acc} = lists:foldl( fun different/2, {lists:reverse(String), String, []}, String ),
+	lists:reverse( Acc ).
+
+task() ->
+	Strings = ["abracadabra", "seesaw", "elk", "grrrrrr", "up", "a"],
+	Shuffleds = [string(X) || X <- Strings],
+	[io:fwrite("~p ~p ~p~n", [X, Y, sameness(X,Y)]) || {X, Y} <- lists:zip(Strings, Shuffleds)].
+
+
+
+different( Character, {[Character], Original, Acc} ) ->
+	try_to_save_last( Character, Original, Acc );
+different( Character, {[Character | T]=Not_useds, Original, Acc} ) ->
+	Different_or_same = different_or_same( [X || X <- T, X =/= Character], Character ),
+	{lists:delete(Different_or_same, Not_useds), Original, [Different_or_same | Acc]};
+different( _Character1, {[Character2 | T], Original, Acc} ) ->
+	{T, Original, [Character2 | Acc]}.
+
+different_or_same( [Different | _T], _Character ) -> Different;
+different_or_same( [], Character ) -> Character.
+
+try_to_save_last( Character, Original_string, Acc ) ->
+	Fun = fun ({X, Y}) -> (X =:= Y) orelse (X =:= Character) end,
+	New_acc = try_to_save_last( lists:splitwith(Fun, lists:zip(lists:reverse(Original_string), [Character | Acc])), [Character | Acc] ),
+	{"", Original_string, New_acc}.
+
+try_to_save_last( {_Not_split, []}, Acc ) -> Acc;
+try_to_save_last( {Last_reversed_zip, First_reversed_zip}, _Acc ) ->
+	{_Last_reversed_original, [Last_character_acc | Last_part_acc]} = lists:unzip( Last_reversed_zip ),
+	{_First_reversed_original, [Character_acc | First_part_acc]} = lists:unzip( First_reversed_zip ),
+	[Character_acc | Last_part_acc] ++ [Last_character_acc | First_part_acc].