35 lines
1.2 KiB
Perl
35 lines
1.2 KiB
Perl
|
:- table galaxy/2.
|
||
|
|
:- table no_galaxy_row/2.
|
||
|
|
:- table no_galaxy_col/2.
|
||
|
|
:- use_module(library(pio)).
|
||
|
|
:- initialization(start, main).
|
||
|
|
|
||
|
|
start :-
|
||
|
|
input('input.txt', Map),
|
||
|
|
findall(Dist, distance(Map, _, _, Dist), Dists),
|
||
|
|
sum_list(Dists, Answer),
|
||
|
|
writef('Answer=%w\n', [Answer]).
|
||
|
|
|
||
|
|
distance(Map, X1-Y1, X2-Y2, Dist) :-
|
||
|
|
galaxy(Map, X1-Y1),
|
||
|
|
galaxy(Map, X2-Y2),
|
||
|
|
(X1 < X2; X1 =:= X2, Y1 < Y2),
|
||
|
|
findall(X, no_galaxy_row(Map, X), EmptyXs),
|
||
|
|
findall(Y, no_galaxy_col(Map, Y), EmptyYs),
|
||
|
|
include(between(X1, X2), EmptyXs, ExpandedX), length(ExpandedX, RowsToAdd),
|
||
|
|
include(between(Y1, Y2), EmptyYs, ExpandedY), length(ExpandedY, ColsToAdd),
|
||
|
|
Dist is abs(X1 - X2) + abs(Y1 - Y2) + RowsToAdd*999999 + ColsToAdd*999999.
|
||
|
|
|
||
|
|
between(End1, End2, N) :- End1 < N, N < End2; End1 > N, N > End2.
|
||
|
|
no_galaxy_row(Map, X) :- nth0(X, Map, Row), maplist([46]>>(true), Row).
|
||
|
|
no_galaxy_col(Map, Y) :- maplist({Y}/[Row]>>(nth0(Y, Row, 46)), Map).
|
||
|
|
|
||
|
|
galaxy(Map, X-Y) :- nth0(X, Map, Row), nth0(Y, Row, 35).
|
||
|
|
|
||
|
|
input(FileName, Map) :- phrase_from_file(lines(Map), FileName).
|
||
|
|
lines([]) --> eos, !.
|
||
|
|
lines([Line|Lines]) --> line(Line), lines(Lines).
|
||
|
|
eos([], []).
|
||
|
|
line([]) --> ( "\n" ; eos ), !.
|
||
|
|
line([L|Ls]) --> [L], line(Ls).
|