Day 7-2

day7.erl

@@ -5,18 +5,23 @@
 solve(InputData) ->
 	Input = binary:split(InputData, <<"\n">>, [trim_all, global]),
 	#{sizes := Sizes} = lists:foldl(fun execute/2, #{cwd => [], sizes => #{}}, Input),
-	{maps:fold(fun adder/3, 0, Sizes), none}.
+	{maps:fold(fun adder/3, 0, Sizes), part2(Sizes)}.
 
 adder(_Path, Size, Total) when Size > 100000 -> Total;
 adder(_Path, Size, Total) -> Size + Total.
 
+part2(#{[] := FullSize} = SizesIn) ->
+	Sizes0 = maps:values(SizesIn),
+	Sizes1 = lists:filter(fun(Size) -> Size > FullSize - 40000000 end, Sizes0),
+	lists:min(Sizes1).
+
 execute(<<"$ cd /">>, State) -> State#{cwd := []};
 execute(<<"$ cd ..">>, #{cwd := [_Cwd | Parent]} = State) -> State#{cwd := Parent};
 execute(<<"$ cd ", Dir/binary>>, #{cwd := Cwd} = State) -> State#{cwd := [Dir | Cwd]};
 execute(<<"$ ls">>, State) -> State;
 execute(<<"dir ", Dir/binary>>, #{cwd := Cwd} = State) -> State#{[Dir | Cwd] => 0};
 execute(FileCommand ,#{cwd := Cwd, sizes := Sizes} = State) ->
-	{Filename, Size} = parse_file_command(FileCommand),
+	{_Filename, Size} = parse_file_command(FileCommand),
 	State#{sizes := add_sizes(Cwd, Size, Sizes)}.
 
 parse_file_command(Command) -> parse_file_command(Command, 0).