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Author SHA1 Message Date
0f5dcc20ce d14p2 for real 2023-12-14 22:24:55 -08:00
a6c506874c first half of part2 seems to work I hate swipl tabling 2023-12-14 13:50:21 -08:00
2 changed files with 121 additions and 7 deletions

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@ -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).

117
14/part2.pl Normal file
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@ -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([], []).