aoc2023/day12.pl

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

:- table ok/3.
ok([], [], []).
ok([0'.|Ts], Cs, [0'.|Rs]) :-
  ok(Ts, Cs, Rs).
ok([0'#|Ts], [C|Cs], [0'#|Rs]) :-
  C1 is C - 1,
  fill(Ts, C1, Rs, Ts1, Rs1),
  ok(Ts1, Cs, Rs1).
ok([0'?|Ts], Cs, [0'.|Rs]) :-
  ok(Ts, Cs, Rs).
ok([0'?|Ts], [C|Cs], [0'#|Rs]) :-
  C1 is C - 1,
  fill(Ts, C1, Rs, Ts1, Rs1),
  ok(Ts1, Cs, Rs1).


:- table fill/5.
fill([],     0, [],       [],  [])  :- !.
fill([T|Ts], 0, [0'.|Rs], Ts,  Rs)  :- !, can_empty(T).
fill([T|Ts], C, [0'#|Rs], Ts1, Rs1) :-
  C > 0, C1 is C - 1,
  can_fill(T), !, fill(Ts, C1, Rs, Ts1, Rs1).

can_fill(0'#).
can_fill(0'?).

can_empty(0'.).
can_empty(0'?).

count(T, C, N) :- bagof(S, ok(T, C, S), Ss), length(Ss, N).
count(T-C,  N) :- count(T, C, N).

examples1 :-
  count(`???.###`,             [1, 1, 3],    1),
  count(`.??..??...?##.`,      [1, 1, 3],    4),
  count(`?#?#?#?#?#?#?#?`,     [1, 3, 1, 6], 1),
  count(`????.#...#...`,       [4, 1, 1],    1),
  count(`????.######..#####.`, [1, 6, 5],    4),
  count(`?###????????`,        [3, 2, 1],    10).


file(Lines) --> sequence(line, Lines).
line(T-C)   --> template(T), " ", clues(C), blanks.
template(T) --> sequence(tchar, T).
tchar(T)    --> [T], {member(T, `?#.`)}.
clues(C)    --> sequence(number, ",", C).


part1(File) :-
  phrase_from_file(file(TCs), File), !,
  maplist(count, TCs, Ns),
  foldl(plus, Ns, 0, N),
  writeln(N).


/*

% oof ouch my memory ☹

count_unfold(T, C, N) :-
  unfold_template(T, T1),
  unfold_clues(C, C1),
  count(T1, C1, N).

unfold_template(T, R) :- unfold_template(5, T, R).
unfold_template(1, T, T) :- !.
unfold_template(N, T, R) :-
  N > 1, N1 is N - 1,
  unfold_template(N1, T, R1),
  append(T, [0'?|R1], R).

unfold_clues(C, R) :- unfold_clues(5, C, R).
unfold_clues(1, C, C) :- !.
unfold_clues(N, C, R) :-
  N > 1, N1 is N - 1,
  unfold_clues(N1, C, R1),
  append(C, R1, R).

examples2 :-
  count_unfold(`???.###`,             [1,1,3],   1),
  count_unfold(`.??..??...?##.`,      [1,1,3],   16384),
  count_unfold(`?#?#?#?#?#?#?#?`,     [1,3,1,6], 1),
  count_unfold(`????.#...#...`,       [4,1,1],   16),
  count_unfold(`????.######..#####.`, [1,6,5],   2500),
  count_unfold(`?###????????`,        [3,2,1],   506250),
  abolish_all_tables.


count_unfold_all(Ls, Ns) :-
  length(Ls, Len),
  count_unfold_all(1, Len, Ls, Ns).
count_unfold_all(_, _,   [],         [])     :- !, abolish_all_tables.
count_unfold_all(I, Len, [T0-C0|Ls], [N|Ns]) :-
  abolish_all_tables,
  unfold_template(T0, T), unfold_clues(C0, C),
  length(T, LenT), length(C, LenC), wildcards(T, W),
  format("[~d/~d] ~w ~w ~w > ", [I, Len, 'T'(LenT), 'C'(LenC), 'W'(W)]), flush,
  !, call_time(count(T, C, N), Time), !,
  format("[~2fs] ~d~n", [Time.wall, N]),
  I1 is I + 1,
  count_unfold_all(I1, Len, Ls, Ns).

wildcards(T, N) :-
  setof(I, nth0(I, T, 0'?), Is), length(Is, N).

part2(File) :-
  abolish_all_tables,
  writeln(go),
  set_prolog_flag(stack_limit, 18_000_000_000),
  set_prolog_flag(table_space, 40_000_000_000),
  phrase_from_file(file(TCs), File), !,
  count_unfold_all(TCs, Ns),
  foldl(plus, Ns, 0, N),
  writeln(N).

*/

% vim: set ft=prolog :