d14p2 for real

14/part1.pl

@@ -1,17 +1,17 @@
 :- use_module(library(pio)).
 :- use_module(library(clpfd)).
 :- initialization(main, main).
+:- table rocks/3.
 
 main([FileName|_]) :-
     input(FileName, Input),
     transpose(Input, Rotated),
     concurrent_maplist([Row, [#|Row]]>>(true), Rotated, Rocks),
-    concurrent_maplist(row_weight, Rocks, Weights),
+    /*concurrent_*/maplist(row_weight, Rocks, Weights),
     sum_list(Weights, W),
     writef('%t\n', [W]).
 
 row_weight(Row, Weight) :-
-    abolish_private_tables, table(rocks/3),
     phrase(rocks(Rocks), Row),
     convlist([N-'#', N]>>(true), Rocks, RockCounts),
     sum_list(RockCounts, Weight),
@@ -24,12 +24,9 @@ rocks([LastN-I, LastN-LastI|Rocks]) -->
 rocks([N-I, LastN-LastI|Rocks]) -->
     [1], rocks([LastN-LastI|Rocks]),
     {I is LastI + 1, N is LastN + 1}.
-rocks([0-I, 0-LastI|Rocks]) -->
-    ['#'], rocks([0-LastI|Rocks]),
-    {I is LastI + 1}.
 rocks([0-I, N-'#', LastN-LastI|Rocks]) -->
-    ['#'], rocks([LastN-LastI|Rocks]),
-    {LastN =\= 0, I is LastI + 1, N is LastN*(2*LastI - LastN + 1) / 2}.
+    [#], rocks([LastN-LastI|Rocks]),
+    {I is LastI + 1, N is LastN*(2*LastI - LastN + 1) / 2}.
 
 % things below are for reading from input file
 input(FileName, Input) :- phrase_from_file(lines(Input), FileName).

14/part2.pl

@@ -0,0 +1,117 @@
+:- use_module(library(pio)).
+:- use_module(library(clpfd)).
+:- initialization(main, main).
+
+main([FileName|_]) :-
+    input(FileName, Input),
+    rolls(Input, 0, [], First-Cycle-Hist),
+    reverse(Hist, [_|TrueHist]),
+    BillionOffset is ((999999999 - First) mod Cycle) + First,
+    nth0(BillionOffset, TrueHist, BillionMap),
+    % maplist({TrueHist}/[M]>>(
+    %     nth0(Nth, TrueHist, M),
+    %     map_weight(M, W),
+    %     writef('Weight(%t) = %t\n', [Nth, W]),
+    %     print(M)), TrueHist),
+    write('======================\n'),
+    print(BillionMap),
+    map_weight(BillionMap, FinalWeight),
+    writef('First = %t, Cycle = %t, FinalOffset = %t, Answer = %t\n',
+           [First, Cycle, BillionOffset, FinalWeight]).
+
+map_weight(Map, W) :- rotate(Map, Rotated), map_weight(Rotated, _, W).
+
+map_weight([_], 0, 0).
+map_weight([Row|Map], RowI, W) :-
+    map_weight(Map, PrevRowI, PrevW),
+    RowI is PrevRowI + 1,
+    include(['O']>>(true), Row, Rocks),
+    length(Rocks, NRocks),
+    W is PrevW + RowI*NRocks.
+
+rolls(Map, N, Hist, First-Cycle-Hist) :-
+    match(Map, Hist, Cycle),
+    First is N - Cycle - 1,
+    !.
+rolls(Map, N, Hist, X) :-
+    roll(Map, NewMap),
+    NextN is N + 1,
+    NewHist = [Map|Hist],
+    rolls(NewMap, NextN, NewHist, X).
+
+match(Map, [Map|_], 1) :- !.
+match(Map, [_|Entries], N) :-
+    match(Map, Entries, NextN),
+    N is NextN + 1.
+
+% North is to the left
+roll(Map, NewMap) :-
+    concurrent_maplist(collapse, Map, NorthCollapsed),
+    rotate(NorthCollapsed, West),
+    concurrent_maplist(collapse, West, WestCollapsed),
+    rotate(WestCollapsed, South),
+    concurrent_maplist(collapse, South, SouthCollapsed),
+    rotate(SouthCollapsed, East),
+    concurrent_maplist(collapse, East, EastCollapsed),
+    rotate(EastCollapsed, NewMap).
+
+rotate(Map, NewMap) :-
+    transpose(Map, X),
+    concurrent_maplist(reverse, X, NewMap).
+
+print(Map) :-
+    rotate(Map, RotMap),
+    append([[_|RealMap], [_]], RotMap),
+    maplist([X]>>(
+        append([_|Y], [_], X),
+        atomics_to_string(Y, S),
+        writef('%t\n', [S])), RealMap),
+    write('\n').
+
+collapse(Row, NewRow) :-
+    phrase(rock_counts(Counts), Row),
+    phrase(condense(Zs), Counts),
+    phrase(reexpand(Zs), NewRow),
+    true.
+
+reexpand([]) --> eos.
+reexpand([N-Next|Rocks]) --> ['#'], stack(N, Next), reexpand(Rocks).
+
+stack(0, 0) --> [], !.
+stack(0, Z) --> {NextZ is Z - 1}, ['.'], stack(0, NextZ), !.
+stack(N, Z) --> {NextZ is Z - 1, NextN is N - 1}, ['O'], stack(NextN, NextZ).
+
+condense([]) --> [0-0-0].
+condense([N-Next|Rocks]) --> [0-I-I, N-z-Next], condense(Rocks), !.
+condense(Rocks) --> [_-_-_], condense(Rocks).
+
+rock_counts([0-0-0]) --> [].
+rock_counts([LastN-I-LastZ, LastN-LastI-LastZ|Rocks]) -->
+    ['.'], rock_counts([LastN-LastI-LastZ|Rocks]),
+    {I is LastI + 1}.
+rock_counts([N-I-LastZ, LastN-LastI-LastZ|Rocks]) -->
+    ['O'], rock_counts([LastN-LastI-LastZ|Rocks]),
+    {I is LastI + 1, N is LastN + 1}.
+rock_counts([0-I-I, LastN-z-Len, LastN-LastI-LastZ|Rocks]) -->
+    ['#'], rock_counts([LastN-LastI-LastZ|Rocks]),
+    {I is LastI + 1, Len is I - LastZ - 1}.
+
+% North is to the left
+input(FileName, Input) :-
+    phrase_from_file(lines(Raw), FileName),
+    concurrent_maplist(pad, Raw, PaddedInput),
+    concurrent_maplist(reverse, PaddedInput, Reversed),
+    transpose(Reversed, Rotated),
+    concurrent_maplist(pad, Rotated, Input).
+
+pad(Row, Rowx) :- append(['#'|Row], ['#'], Rowx).
+
+lines([]) --> eos, !.
+lines([Line|Lines]) --> line(Line), lines(Lines).
+
+line([]) --> "\n"; eos.
+line(['O'|Chars]) --> "O", line(Chars).
+line(['.'|Chars]) --> ".", line(Chars).
+line(['#'|Chars]) --> "#", line(Chars).
+
+eos([], []).