-module(drzewobinarne).
-export([empty/0, insert/3, has_value/2, has_value_exceptions/2, generate_from_list/1, generate_random_tree/0]).

empty() -> {node, 'nil'}.

%Wstawianie elementu do drzewa
insert(Key, Val, {node, 'nil'}) ->
    {node, {Key, Val, {node, 'nil'}, {node, 'nil'}}};
insert(NewKey, NewVal, {node, {Key, Val, Smaller, Larger}}) when NewKey < Key ->
    {node, {Key, Val, insert(NewKey, NewVal, Smaller), Larger}};
insert(NewKey, NewVal, {node, {Key, Val, Smaller, Larger}}) when NewKey > Key ->
    {node, {Key, Val, Smaller, insert(NewKey, NewVal, Larger)}};
insert(Key, Val, {node, {Key, _, Smaller, Larger}}) ->
    {node, {Key, Val, Smaller, Larger}}.

%Generacja losowego drzewa (liczby)
generate_random_tree() -> generate_from_list([{K, V} || K <- rand:uniform(20), V <- rand:uniform(20), _ <- lists:seq(1, 10)]).

%Generacja drzewa z listy
generate_from_list([]) -> empty();
generate_from_list([{K,V}|T]) -> insert(K, V, generate_from_list(T)).

%Zwinięcie drzewa do listy (3 dowolne metody)


%Szukanie elementu wersja normalana
has_value(_, {node, 'nil'}) ->
false;
has_value(Val, {node, {_, Val, _, _}}) ->
true;
has_value(Val, {node, {_, _, Left, Right}}) ->
case has_value(Val, Left) of
true -> true;
false -> has_value(Val, Right)
end.

%Szukanie elementu wersja z wyjątkami
has_value_exceptions(Val, Tree) ->
try has_value_exceptions1(Val, Tree) of
false -> false
catch
true -> true
end.

has_value_exceptions1(_, {node, 'nil'}) ->
false;
has_value_exceptions1(Val, {node, {_, Val, _, _}}) ->
throw(true);
has_value_exceptions1(Val, {node, {_, _, Left, Right}}) ->
has_value_exceptions1(Val, Left),
has_value_exceptions1(Val, Right).