diff --git a/11/part1.pl b/11/part1.pl
index abadb50..a4ef28d 100644
--- a/11/part1.pl
+++ b/11/part1.pl
@@ -1,34 +1,31 @@
 :- use_module(library(pio)).
 :- initialization(main, main).
 
-:- 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 of manhattan distances is sum of distances on all axes.
+    findall(Dist, distance(_, Map, _, Dist), Dists),
     sum_list(Dists, Sum),
     writef('Answer=%t\n', [Sum]).
 
-distance(Axis, Map, X1, X2, Dist) :-
-    true_coord(Axis, Map, X1, TrueX1), true_coord(Axis, Map, X2, TrueX2),
-    Dist is abs(TrueX1 - TrueX2).
+distance(Axis, Map, A-B, Dist) :-
+    true_coords(Axis, Map, TrueNs),
+    member(A-ACount, TrueNs), member(B-BCount, TrueNs), A < B,
+    Dist is (B - A) * ACount * BCount.
 
-true_coord(Axis, Map, X, TrueX) :-
-    findall(E, (call(galaxies, Axis, Map, E-0), E < X), EmptyRows),
-    length(EmptyRows, ToAdd),
-    TrueX is X + ToAdd.
+true_coords(x, Map, TrueXs) :-
+    NextX = [Row, LastX-_, X-Count]>>(
+        sum_list(Row, Count),
+        (Count = 0 -> X is LastX + 2; X is LastX + 1)),
+    scanl(NextX, Map, -1-0, Xs), Xs = [_ | TrueXs].
 
-% 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).
+true_coords(y, [FirstRow | Map], TrueYs) :-
+    foldl(add_vectors, Map, FirstRow, CountY),
+    NextY = [Count, LastY-_, Y-Count]>>(
+        Count = 0 -> Y is LastY + 2; Y is LastY + 1),
+    scanl(NextY, CountY, -1-0, Ys), Ys = [_ | TrueYs].
+
+add_vectors([], [], []).
+add_vectors([A | V1], [B | V2], [C | V]) :- C is A + B, add_vectors(V1, V2, V).
 
 input(FileName, Map) :- phrase_from_file(lines(Map), FileName).
 lines([]) --> eos, !.
diff --git a/11/part2.pl b/11/part2.pl
index 76994cd..4740f40 100644
--- a/11/part2.pl
+++ b/11/part2.pl
@@ -1,34 +1,31 @@
 :- use_module(library(pio)).
 :- initialization(main, main).
 
-:- 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 of manhattan distances is sum of distances on all axes.
+    findall(Dist, distance(_, Map, _, Dist), Dists),
     sum_list(Dists, Sum),
     writef('Answer=%t\n', [Sum]).
 
-distance(Axis, Map, X1, X2, Dist) :-
-    true_coord(Axis, Map, X1, TrueX1), true_coord(Axis, Map, X2, TrueX2),
-    Dist is abs(TrueX1 - TrueX2).
+distance(Axis, Map, A-B, Dist) :-
+    true_coords(Axis, Map, TrueNs),
+    member(A-ACount, TrueNs), member(B-BCount, TrueNs), A < B,
+    Dist is (B - A) * ACount * BCount.
 
-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.
+true_coords(x, Map, TrueXs) :-
+    NextX = [Row, LastX-_, X-Count]>>(
+        sum_list(Row, Count),
+        (Count = 0 -> X is LastX + 1000000; X is LastX + 1)),
+    scanl(NextX, Map, -1-0, Xs), Xs = [_ | TrueXs].
 
-% 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).
+true_coords(y, [FirstRow | Map], TrueYs) :-
+    foldl(add_vectors, Map, FirstRow, CountY),
+    NextY = [Count, LastY-_, Y-Count]>>(
+        Count = 0 -> Y is LastY + 1000000; Y is LastY + 1),
+    scanl(NextY, CountY, -1-0, Ys), Ys = [_ | TrueYs].
+
+add_vectors([], [], []).
+add_vectors([A | V1], [B | V2], [C | V]) :- C is A + B, add_vectors(V1, V2, V).
 
 input(FileName, Map) :- phrase_from_file(lines(Map), FileName).
 lines([]) --> eos, !.