This commit is contained in:
Dory 2023-12-17 11:30:10 -08:00
parent edcc8f4dba
commit ce7568e5fc

91
17/part2.pl Normal file
View File

@ -0,0 +1,91 @@
:- use_module(library(pio)).
:- use_module(library(dcg/basics)).
:- initialization(main, main).
% :- table cost/3.
% :- table to_key/3.
main([FileName|_]) :-
input(FileName, Map),
length(Map, EndXx), EndX is EndXx - 1,
Start1 = 0-0-horz, Start2 = 0-0-vert,
to_key(Start1, K1), to_key(Start2, K2), Costs = cost{}.put(K1, 0).put(K2, 0),
Map = [Row0|_], length(Row0, EndYx), EndY is EndYx - 1,
heur(0-0, EndX-EndY, Heur0),
list_to_heap([Heur0-Start1, Heur0-Start2], Queue),
astar(Map, Costs, Queue, EndX-EndY, N),
write(N), nl.
astar(_Map, Costs, PQueue, DestX-DestY, N) :-
get_from_heap(PQueue, _, X-Y-From, _), X = DestX, Y = DestY,
to_key(DestX-DestY-From, FromKey), N = Costs.FromKey, !.
astar(Map, Gs, PQueue, DestX-DestY, N) :-
get_from_heap(PQueue, _, X-Y-From, PQueueAfterPop),
to_key(X-Y-From, CurrentKey), CurrentG = Gs.CurrentKey,
findall(To-Cost, next(Map, X-Y-From, To, Cost), Neighbors),
foldl(add_neighbor(CurrentG, DestX, DestY),
Neighbors, PQueueAfterPop-Gs, NewPQueue-NewGs),
astar(Map, NewGs, NewPQueue, DestX-DestY, N).
add_neighbor(CurrentG, DestX, DestY, (X-Y-Dir)-Cost, HeapIn-GsIn, HeapOut-GsOut) :-
NewGCandidate is CurrentG + Cost,
to_key(X-Y-Dir, Key), ExistingG = GsIn.get(Key, 9999999),
( NewGCandidate < ExistingG
-> NewG = NewGCandidate, GsOut = GsIn.put(Key, NewG),
heur(X-Y, DestX-DestY, Heur), Weight is NewG + Heur,
( get_from_heap(HeapIn, _, X-Y-Dir, _), HeapOut = HeapIn
; add_to_heap(HeapIn, Weight, X-Y-Dir, HeapOut)
)
; GsOut = GsIn, HeapOut = HeapIn
).
to_key(X-Y-horz, Key) :- Key is 0 + Y*10 + X* 10000.
to_key(X-Y-vert, Key) :- Key is 1 + Y*10 + X* 10000.
next(Map, X-Y-horz, NextX-Y-vert, Cost) :-
LowX1 is X - 10, HighX1 is X - 4,
LowX2 is X + 4, HighX2 is X + 10,
(between(LowX1, HighX1, NextX); between(LowX2, HighX2, NextX)),
vert(Map, X-Y, NextX, Cost).
next(Map, X-Y-vert, X-NextY-horz, Cost) :-
LowY1 is Y - 10, HighY1 is Y - 4,
LowY2 is Y + 4, HighY2 is Y + 10,
(between(LowY1, HighY1, NextY); between(LowY2, HighY2, NextY)),
horz(Map, X-Y, NextY, Cost).
vert(Map, X-Y, NextX, Cost) :-
cost(Map, NextX-Y, _),
findall(
Ci,
( (X < NextX -> between(X, NextX, Xi); between(NextX, X, Xi)),
Xi =\= X,
cost(Map, Xi-Y, Ci)),
Costs),
sum_list(Costs, Cost).
% Cost = Costs.
horz(Map, X-Y, NextY, Cost) :-
cost(Map, X-NextY, _),
findall(
Ci,
( (Y < NextY -> between(Y, NextY, Yi); between(NextY, Y, Yi)),
Yi =\= Y,
cost(Map, X-Yi, Ci)),
Costs),
sum_list(Costs, Cost).
% Cost = Costs.
heur(X1-Y1, X2-Y2, Dist) :- Dist is sqrt((X1 - X2)**2 + (Y1 - Y2)**2).
cost(Map, X-Y, Cost) :- nth0(X, Map, Row), nth0(Y, Row, Cost).
print(Map) :- maplist([X]>>(atomic_list_concat(X, N), write(N), nl), Map).
input(Name, Map) :- phrase_from_file(lines(Map), Name).
lines([]) --> eos, !.
lines([Nums|Lines]) -->
line(Line), lines(Lines),
{maplist([C, N]>>(N is C - 48), Line, Nums)}.
line(Nums) --> digits(Nums), "\n".