1 bb300da9 2025-12-04 lh parse_input(File) :-
 2 bb300da9 2025-12-04 lh     read_file_to_string(File, Content, []),
 3 bb300da9 2025-12-04 lh     split_string(Content, "\n", "", Lines0),
 4 bb300da9 2025-12-04 lh     exclude(=(""), Lines0, Lines),
 5 bb300da9 2025-12-04 lh     length(Lines, Length),
 6 bb300da9 2025-12-04 lh     numlist(1, Length, Ys),
 7 bb300da9 2025-12-04 lh     maplist(assert_line, Lines, Ys).
 8 bb300da9 2025-12-04 lh 
 9 bb300da9 2025-12-04 lh assert_line(Line, Y) :-
10 bb300da9 2025-12-04 lh     string_chars(Line, Chars),
11 bb300da9 2025-12-04 lh     assert_chars(Chars, 1, Y).
12 bb300da9 2025-12-04 lh 
13 bb300da9 2025-12-04 lh assert_chars([], _, _).
14 bb300da9 2025-12-04 lh assert_chars([C|Rest], X, Y) :-
15 bb300da9 2025-12-04 lh     assert_field(C, X, Y),
16 bb300da9 2025-12-04 lh     X2 is X + 1,
17 bb300da9 2025-12-04 lh     assert_chars(Rest, X2, Y).
18 bb300da9 2025-12-04 lh 
19 bb300da9 2025-12-04 lh assert_field('@', X, Y) :-
20 bb300da9 2025-12-04 lh     assertz(roll(X, Y)).
21 bb300da9 2025-12-04 lh assert_field(_, _, _).
22 bb300da9 2025-12-04 lh 
23 bb300da9 2025-12-04 lh forklift_access(X, Y) :-
24 bb300da9 2025-12-04 lh     roll(X, Y),
25 bb300da9 2025-12-04 lh     neighbour_count(X, Y, N),
26 bb300da9 2025-12-04 lh     N < 4.
27 bb300da9 2025-12-04 lh 
28 bb300da9 2025-12-04 lh neighbour_offset(DX, DY) :-
29 bb300da9 2025-12-04 lh     between(-1, 1, DX),
30 bb300da9 2025-12-04 lh     between(-1, 1, DY),
31 bb300da9 2025-12-04 lh     \+ (DX = 0, DY = 0).
32 bb300da9 2025-12-04 lh 
33 bb300da9 2025-12-04 lh has_neighbour(X, Y, DX, DY) :-
34 bb300da9 2025-12-04 lh     neighbour_offset(DX, DY),
35 bb300da9 2025-12-04 lh     NX is X + DX,
36 bb300da9 2025-12-04 lh     NY is Y + DY,
37 bb300da9 2025-12-04 lh     roll(NX, NY).
38 bb300da9 2025-12-04 lh 
39 bb300da9 2025-12-04 lh neighbour_count(X, Y, N) :-
40 bb300da9 2025-12-04 lh     aggregate_all(count, has_neighbour(X, Y, _, _), N).
41 bb300da9 2025-12-04 lh 
42 bb300da9 2025-12-04 lh task1(N) :-
43 bb300da9 2025-12-04 lh     aggregate_all(count, forklift_access(_, _), N).
44 bb300da9 2025-12-04 lh 
45 bb300da9 2025-12-04 lh task2_(C0, Total) :-
46 bb300da9 2025-12-04 lh     findall(roll(X, Y), forklift_access(X, Y), List),
47 bb300da9 2025-12-04 lh     maplist(retract, List),
48 bb300da9 2025-12-04 lh     length(List, C1),
49 bb300da9 2025-12-04 lh     C3 is C0 + C1,
50 bb300da9 2025-12-04 lh     ( C1 = 0
51 bb300da9 2025-12-04 lh     -> Total is C3
52 bb300da9 2025-12-04 lh     ;  task2_(C3, Total)
53 bb300da9 2025-12-04 lh     ).
54 bb300da9 2025-12-04 lh 
55 bb300da9 2025-12-04 lh task2(N) :-
56 bb300da9 2025-12-04 lh     task2_(0, N).
57 bb300da9 2025-12-04 lh 
58 bb300da9 2025-12-04 lh :-
59 bb300da9 2025-12-04 lh     parse_input("input/04.txt"),
60 bb300da9 2025-12-04 lh     task1(Task1),
61 bb300da9 2025-12-04 lh     task2(Task2),
62 bb300da9 2025-12-04 lh     format("~d ~d~n", [Task1, Task2]).