:- use_module(library(dcg/basics)).
:- use_module(library(clpfd)).

answers([], []).
answers(Group, [Answer|Answers]) :-
    append(Answer, [10 | Rest], Group),
    answers(Rest, Answers).
answers(Group, [Answer]) :-
    append(Answer, [10], Group).
answers(Group, [Group]).

groups(Str, [Answers | Groups]) :-
    append(Group, [10, 10 | Rest], Str),
    answers(Group, Answers),
    groups(Rest, Groups).
groups(Str, [Answer]) :-
    answers(Str, Answer).

unique_1(Answers, Count) :-
    [A| As] = Answers,
    foldl(union, As, A, Unique),
    length(Unique, Count).

unique_2(Answers, Count) :-
    [A| As] = Answers,
    foldl(intersection, As, A, Unique),
    length(Unique, Count).

main(Part1, Part2) :-
    read_file_to_codes('advent_6_inp.txt', Codes, []),
    groups(Codes, Groups),
    maplist(unique_1, Groups, Count1),
    sum(Count1, #=, Part1),
    maplist(unique_2, Groups, Count2),
    sum(Count2, #=, Part2), !.