faster d11

11/part1.naive.pl

@@ -0,0 +1,35 @@
+:- op(700, xfx, before).
+:- 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, (galaxy(Map, A), galaxy(Map, B), A before B,
+                   distance(Map, A, B, Dist)),
+            Dists),
+    sum_list(Dists, Answer),
+    writef('Answer=%w\n', [Answer]).
+
+distance(Map, X1-Y1, X2-Y2, Dist) :-
+    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 + ColsToAdd.
+
+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).
+before(X1-Y1, X2-Y2) :- X1 < X2; X1 =:= X2, Y1 < Y2.
+
+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).

11/part1.pl

@@ -1,35 +1,38 @@
-:- op(700, xfx, before).
-:- table galaxy/2.
-:- table no_galaxy_row/2.
-:- table no_galaxy_col/2.
 :- use_module(library(pio)).
-:- initialization(start, main).
+:- initialization(main, main).
 
-start :-
-    input('input.txt', Map),
-    findall(Dist, (galaxy(Map, A), galaxy(Map, B), A before B,
-                   distance(Map, A, B, Dist)),
+:- table galaxies/3.
+
+main([FileName | _]) :-
+    input(FileName, Map),
+    findall(Dist,
+            (   galaxies(Axis, Map, A-ACount), ACount =\= 0,
+                galaxies(Axis, Map, B-BCount), BCount =\= 0,
+                A < B,
+                distance(Axis, Map, A, B, DistPair),
+                Dist is DistPair * ACount * BCount),
             Dists),
-    sum_list(Dists, Answer),
-    writef('Answer=%w\n', [Answer]).
+    % Sum of manhattan distances is sum of distances on all axes.
+    sum_list(Dists, Sum),
+    writef('Answer=%t\n', [Sum]).
 
-distance(Map, X1-Y1, X2-Y2, Dist) :-
-    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 + ColsToAdd.
+distance(Axis, Map, X1, X2, Dist) :-
+    true_coord(Axis, Map, X1, TrueX1), true_coord(Axis, Map, X2, TrueX2),
+    Dist is abs(TrueX1 - TrueX2).
 
-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).
+true_coord(Axis, Map, X, TrueX) :-
+    findall(E, (call(galaxies, Axis, Map, E-0), E < X), EmptyRows),
+    length(EmptyRows, ToAdd),
+    TrueX is X + ToAdd.
 
-galaxy(Map, X-Y) :- nth0(X, Map, Row), nth0(Y, Row, 35).
-before(X1-Y1, X2-Y2) :- X1 < X2; X1 =:= X2, Y1 < Y2.
+% galaxies(Axis, Map, X-Count): There are Count galaxies at coordinate X on Axis
+galaxies(x, Map, X-Count) :- nth0(X, Map, Row), foldl(plus, Row, 0, Count).
+galaxies(y, Map, Y-Count) :-
+    foldl({Y}/[Row, V0, V]>>(nth0(Y, Row, C), V is V0 + C), Map, 0, Count).
 
 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).
+line([L|Ls]) --> ([C], {C =:= 35 -> L = 1; L = 0}), line(Ls).
+eos([], []).

11/part2.naive.pl

@@ -0,0 +1,35 @@
+:- op(700, xfx, before).
+:- 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, (galaxy(Map, A), galaxy(Map, B), A before B,
+                   distance(Map, A, B, Dist)),
+            Dists),
+    sum_list(Dists, Answer),
+    writef('Answer=%w\n', [Answer]).
+
+distance(Map, X1-Y1, X2-Y2, Dist) :-
+    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).
+before(X1-Y1, X2-Y2) :- X1 < X2; X1 =:= X2, Y1 < Y2.
+
+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).

11/part2.pl

@@ -1,35 +1,38 @@
-:- op(700, xfx, before).
-:- table galaxy/2.
-:- table no_galaxy_row/2.
-:- table no_galaxy_col/2.
 :- use_module(library(pio)).
-:- initialization(start, main).
+:- initialization(main, main).
 
-start :-
-    input('input.txt', Map),
-    findall(Dist, (galaxy(Map, A), galaxy(Map, B), A before B,
-                   distance(Map, A, B, Dist)),
+:- table galaxies/3.
+
+main([FileName | _]) :-
+    input(FileName, Map),
+    findall(Dist,
+            (   galaxies(Axis, Map, A-ACount), ACount =\= 0,
+                galaxies(Axis, Map, B-BCount), BCount =\= 0,
+                A < B,
+                distance(Axis, Map, A, B, DistPair),
+                Dist is DistPair * ACount * BCount),
             Dists),
-    sum_list(Dists, Answer),
-    writef('Answer=%w\n', [Answer]).
+    % Sum of manhattan distances is sum of distances on all axes.
+    sum_list(Dists, Sum),
+    writef('Answer=%t\n', [Sum]).
 
-distance(Map, X1-Y1, X2-Y2, Dist) :-
-    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.
+distance(Axis, Map, X1, X2, Dist) :-
+    true_coord(Axis, Map, X1, TrueX1), true_coord(Axis, Map, X2, TrueX2),
+    Dist is abs(TrueX1 - TrueX2).
 
-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).
+true_coord(Axis, Map, X, TrueX) :-
+    findall(E, (call(galaxies, Axis, Map, E-0), E < X), EmptyRows),
+    length(EmptyRows, ToAdd),
+    TrueX is X + ToAdd*999999.
 
-galaxy(Map, X-Y) :- nth0(X, Map, Row), nth0(Y, Row, 35).
-before(X1-Y1, X2-Y2) :- X1 < X2; X1 =:= X2, Y1 < Y2.
+% galaxies(Axis, Map, X-Count): There are Count galaxies at coordinate X on Axis
+galaxies(x, Map, X-Count) :- nth0(X, Map, Row), foldl(plus, Row, 0, Count).
+galaxies(y, Map, Y-Count) :-
+    foldl({Y}/[Row, V0, V]>>(nth0(Y, Row, C), V is V0 + C), Map, 0, Count).
 
 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).
+line([L|Ls]) --> ([C], {C =:= 35 -> L = 1; L = 0}), line(Ls).
+eos([], []).