scarecrw's recent activity
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Comment on Day 9: Movie Theater in ~comp.advent_of_code
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Comment on Day 8: Playground in ~comp.advent_of_code
scarecrw LinkCatching up (poorly) on the last couple of days. I found a union-find pack which took out most of the hard work, though the rest of my code is still terribly inefficient. Oh well, just gotta keep...Catching up (poorly) on the last couple of days. I found a union-find pack which took out most of the hard work, though the rest of my code is still terribly inefficient. Oh well, just gotta keep the momentum going for now.
Prolog Solution
:- ['src/util.pl']. :- initialization(main). :- use_module(library(record)). :- use_module(library(union_find)). :- record point(x:integer=0, y:integer=0, z:integer=0). main:- phrase_from_file(input(Points), 'inputs/day08.txt'), Merges = 1000, findall((D, P1, P2), point_pair(Points, P1, P2, D), PointPairs), sort(PointPairs, PointPairs1), maplist([(_, P1, P2), R]>>(nth1(I, Points, P1), nth1(J, Points, P2), R = (I, J)), PointPairs1, PointPairs2), solve_1(Points, PointPairs2, Merges, Result1), write("Part 1: "), write(Result1), nl, solve_2(Points, PointPairs2, Result2), write("Part 2: "), write(Result2), nl, halt. solve_1(Points, PointPairs, Merges, Result):- take(Merges, PointPairs, PointPairs1), length(Points, N), union_find(UF, N), maplist([(P1, P2)]>>(union(UF, P1, P2)), PointPairs1), disjoint_sets(UF, DS), maplist(length, DS, Lengths), sort(Lengths, Lengths1), reverse(Lengths1, Lengths2), take(3, Lengths2, ToMult), prod_list(ToMult, Result). solve_2(Points, PointPairs, Result):- length(Points, N), union_find(UF, N), solve_2_rec(UF, PointPairs, (A, B)), nth1(A, Points, P1), nth1(B, Points, P2), point_x(P1, X1), point_x(P2, X2), Result is X1 * X2. solve_2_rec(UF, [(P1, P2)|_], LastPair):- disjoint_sets(UF, DS), length(DS, L), L == 2, find(UF, P1, R1), find(UF, P2, R2), R1 =\= R2, LastPair = (P1, P2). solve_2_rec(UF, [(P1, P2)|Pairs], LastPair):- union(UF, P1, P2), solve_2_rec(UF, Pairs, LastPair). point_pair(Points, P1, P2, Distance):- member(P1, Points), member(P2, Points), distance_sq(P1, P2, Distance), Distance =\= 0, point_x(P1, X1), point_y(P1, Y1), point_z(P1, Z1), point_x(P2, X2), point_y(P2, Y2), point_z(P2, Z2), (X1 > X2 ; (X1 == X2, Y1 > Y2) ; (X1 == X2, Y1 == Y2, Z1 > Z2)). distance_sq(Point1, Point2, Distance):- point_x(Point1, X1), point_y(Point1, Y1), point_z(Point1, Z1), point_x(Point2, X2), point_y(Point2, Y2), point_z(Point2, Z2), Distance is (X1 - X2)^2 + (Y1 - Y2)^2 + (Z1 - Z2)^2. input([Point|Rest]) --> point_dcg(Point), "\n", input(Rest). input([Point]) --> point_dcg(Point). point_dcg(Point) --> number_dcg(X), ",", number_dcg(Y), ",", number_dcg(Z), { make_point([x(X), y(Y), z(Z)], Point) }. -
Comment on Day 6: Trash Compactor in ~comp.advent_of_code
scarecrw Link ParentThe problem is that when you pass params to operate in part 2, it isn't a numpy array, so when numpy.prod() auto-converts it to one, it defaults the datatype to int32 and overflows. You can fix it...The problem is that when you pass
paramstooperatein part 2, it isn't a numpy array, so whennumpy.prod()auto-converts it to one, it defaults the datatype toint32and overflows. You can fix it withnumpy.prod(params, dtype='uint64').As for the rotation, using
list(zip(*inputs))[::-1]is a neat trick if you want to do the rotations yourself. -
Comment on Day 7: Laboratories in ~comp.advent_of_code
scarecrw (edited )LinkPretty easy day for the problem itself, so I used the opportunity to try a couple new things: DCGs and "Association Lists" (why does every language have to have their own name for this?). I'm not...Pretty easy day for the problem itself, so I used the opportunity to try a couple new things: DCGs and "Association Lists" (why does every language have to have their own name for this?).
I'm not convinced using a DCG for this style of parsing made it any easier (it certainly didn't make it more succinct), but I can certainly see how it could be useful for more advanced parsing.
I have to say, while Prolog is growing on me, I'm still feeling silly writing ~9 lines to update a couple values in a data structure. It's not that it's that hard, I'm just hoping there's a more idiomatic approach I don't know about.
Prolog Solution
:- initialization(main). main:- phrase_from_file(input(StartingColumn, Rows), 'inputs/day07.txt'), list_to_assoc([StartingColumn-1], Beams), foldl(process_line, Rows, (Beams, 0), (TotalBeams, Result1)), assoc_to_values(TotalBeams, BeamCounts), sum_list(BeamCounts, Result2), format('Part 1: ~w~n', [Result1]), format('Part 2: ~w~n', [Result2]), halt. process_line([], State, State). process_line([Splitter|Rest], (Beams, Splits), (ResBeams, Splits1)):- get_assoc(Splitter, Beams, _), process_line(Rest, (Beams, Splits), (RecBeams, RecSplits)), split_beams(Splitter, RecBeams, ResBeams), succ(RecSplits, Splits1). process_line([_|Rest], State, ResultingState):- process_line(Rest, State, ResultingState). split_beams(Splitter, Beams, ResBeams):- get_assoc(Splitter, Beams, Count), succ(L, Splitter), succ(Splitter, R), (get_assoc(L, Beams, LCount) ; LCount = 0), (get_assoc(R, Beams, RCount) ; RCount = 0), del_assoc(Splitter, Beams, _, Beams1), LCountNew is LCount + Count, RCountNew is RCount + Count, put_assoc(L, Beams1, LCountNew, Beams2), put_assoc(R, Beams2, RCountNew, ResBeams). % Parsing input(StartingColumn, Rows) --> starting_column(StartingColumn, 0), "\n", rows(Rows). starting_column(StartingColumn, Idx) --> ".", { succ(Idx, Idx1) }, starting_column(StartingColumn, Idx1). starting_column(StartingColumn, StartingColumn) --> "S", rest_of_line. rest_of_line --> ".", rest_of_line ; []. rows([Row]) --> row(Row, 0). rows([Row|Rest]) --> row(Row, 0), "\n", rows(Rest). row(Row, Idx) --> ".", { succ(Idx, Idx1) }, row(Row, Idx1). row(Row, Idx) --> "^", { succ(Idx, Idx1) }, row(RowRest, Idx1), {Row = [Idx|RowRest]}. row([], _) --> []. -
Comment on Day 6: Trash Compactor in ~comp.advent_of_code
scarecrw (edited )LinkAnother day down, though this was mostly just a bit annoying. I did add a few useful tools to my saved utilities: transpose/2, split_list/3, and prod_list/2. Not sure if they'll be useful in...Another day down, though this was mostly just a bit annoying. I did add a few useful tools to my saved utilities:
transpose/2,split_list/3, andprod_list/2. Not sure if they'll be useful in future days, but I thought they were general enough to keep.Prolog Solution
:- ['src/util.pl']. :- initialization(main). main:- read_file_to_strings('inputs/day06.txt', Lines), parse_input_1(Lines, Vals, Ops), maplist(solve, Ops, Vals, Nums), sumlist(Nums, Result1), write("Part 1: "), write(Result1), nl, parse_input_2(Lines, Vals2, Ops2), maplist(solve, Ops2, Vals2, Nums2), sumlist(Nums2, Result2), write("Part 2: "), write(Result2), nl, halt. solve("+", Vals, Result):- sum_list(Vals, Result). solve("*", Vals, Result):- prod_list(Vals, Result). parse_input_1(Lines, Vals, Ops):- maplist([S]>>split_string(S, " ", " "), Lines, SplitLines), last(SplitLines, Ops), append(ValStrings, [Ops], SplitLines), maplist(maplist(string_number), ValStrings, ValRows), transpose(ValRows, Vals). parse_input_2(Lines, Vals, Ops):- last(Lines, OpsString), append(OrigValStrings, [OpsString], Lines), split_string(OpsString, " ", " ", Ops), maplist(string_chars, OrigValStrings, Chars), transpose(Chars, FlippedChars), maplist(exclude(=(' ')), FlippedChars, FilteredChars), maplist([C, S]>>string_chars(S, C), FilteredChars, FlippedStrings), split_list(FlippedStrings, "", ValStrings), maplist(maplist(string_number), ValStrings, Vals).Utilities
transpose([], []). transpose([L], R):- maplist([X, V]>>(V = [X]), L, R). transpose([H|T], R):- transpose(T, RecResult), maplist([X,Y,Z]>>(Z = [X|Y]), H, RecResult, R). split_list(List, Delimiter, Result):- split_list(List, Delimiter, [], Result). split_list([], _, Acc, [Acc]). split_list([Delimiter], Delimiter, Acc, [Acc, []]). split_list([Delimiter|T], Delimiter, Acc, Result):- split_list(T, Delimiter, [], Result1), Result = [Acc|Result1]. split_list([H|T], Delimiter, Acc, Result):- Acc1 = [H|Acc], split_list(T, Delimiter, Acc1, Result). prod_list(List, Result):- foldl([A,B,C]>>(C is A * B), List, 1, Result). -
Comment on Day 5: Cafeteria in ~comp.advent_of_code
scarecrw (edited )LinkVery much needed a good day after yesterday frustrated me so much. It just seemed like yesterday everything I tried with the language went wrong, and today it fell together nicely. Nothing...Very much needed a good day after yesterday frustrated me so much. It just seemed like yesterday everything I tried with the language went wrong, and today it fell together nicely.
Nothing creative on the algorithmic front; I suppose there may be some efficiency gains to be had on both parts by keeping ranges sorted, but the list was short enough it didn't matter.
Prolog Solution
:- ['src/util.pl']. parse_range(RangeString, [Start, End]):- split_string(RangeString, "-", "", [A, B]), number_string(Start, A), number_string(End, B). in_ranges(Ranges, ID):- member([Start, End], Ranges), between(Start, End, ID). overlap([S1, E1], [S2, E2]):- S1 =< E2, S2 =< E1. merge_range_rangelist(Range, RangeList, Result):- partition(overlap(Range), RangeList, OverlappingRanges, OtherRanges), flatten([Range|OverlappingRanges], EndPoints), min_list(EndPoints, Start), max_list(EndPoints, End), Result = [[Start, End]|OtherRanges]. range_size([A, B], RangeSize):- RangeSize is B - A + 1. main:- Filename = 'inputs/day05.txt', read_file_to_strings(Filename, Lines), append(RangeStrings, [""|IDStrings], Lines), maplist(parse_range, RangeStrings, Ranges), maplist(string_number, IDStrings, IDs), include(in_ranges(Ranges), IDs, FreshIDs), length(FreshIDs, Result1), write("Part 1: "), write(Result1), nl, foldl(merge_range_rangelist, Ranges, [], MergedRanges), maplist(range_size, MergedRanges, RangeSizes), sumlist(RangeSizes, Result2), write("Part 2: "), write(Result2), nl, halt. :- initialization(main).I tried reading up on difference lists and DCGs this afternoon and did not get anywhere with it. I'll have to give it another go with a clearer head.
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Comment on Day 4: Printing Department in ~comp.advent_of_code
scarecrw (edited )LinkOver two hours to write and over a minute to run... Yesterday I would have said Prolog didn't seem so bad and I was getting a feel for things, today I spent the better part of an hour getting a...Over two hours to write and over a minute to run...
Yesterday I would have said Prolog didn't seem so bad and I was getting a feel for things, today I spent the better part of an hour getting a Moore neighborhood to work.
Real tired and pretty disappointed after this one. Hopefully get a second wind with some free time this weekend.
Prolog Solution
:- ['src/util.pl']. :- table contains_paper/3. contains_paper(Grid, 0, Position):- Position = (RowIndex, ColIndex), nth0(RowIndex, Grid, Row), string_chars(Row, RowChars), nth0(ColIndex, RowChars, Char), Char = '@'. contains_paper(Grid, Step, Position):- succ(Step1, Step), contains_paper(Grid, Step1, Position), not(forkliftable(Grid, Step1, Position)). forkliftable(Grid, Step, Position):- contains_paper(Grid, Step, Position), findall(Pos, neighbor(Position, Pos), Neighbors), count(contains_paper(Grid, Step), Neighbors, NeighborPaper), NeighborPaper < 4. neighbor(Position1, Position2):- Position1 = (Row1, Col1), between(-1, 1, DR), between(-1, 1, DC), (DR, DC) \= (0, 0), Row2 is Row1 + DR, Col2 is Col1 + DC, Position2 = (Row2, Col2). paper_removed(Grid, Step, PaperRemoved):- findall(Pos, contains_paper(Grid, 0, Pos), OriginalPaper), findall(Pos, contains_paper(Grid, Step, Pos), FinalPaper), length(OriginalPaper, OriginalCount), length(FinalPaper, FinalCount), PaperRemoved is OriginalCount - FinalCount. main:- Filename = 'inputs/day04.txt', read_file_to_strings(Filename, Grid), paper_removed(Grid, 1, Result1), write("Part 1: "), write(Result1), nl, paper_removed(Grid, 100, Result2), write("Part 2: "), write(Result2), nl, halt. :- initialization(main). -
Comment on Day 3: Lobby in ~comp.advent_of_code
scarecrw Link ParentI'm hoping someone has an actually clean fix, as I've run into that in the past without much luck. Couple of ideas: Reverse the list, then iterate from 11...0, as list[n:] works fine. Use an...I'm hoping someone has an actually clean fix, as I've run into that in the past without much luck.
Couple of ideas:
- Reverse the list, then iterate from 11...0, as
list[n:]works fine. - Use an in-line conditional
list[:n] if n else list
- Reverse the list, then iterate from 11...0, as
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Comment on Advent of Code starts tomorrow/tonight! Are you participating? Do you have any specific plans for this year? in ~comp.advent_of_code
scarecrw Link ParentI hope you enjoy it! The days get harder as they progress, and later days often require either improved algorithms or optimizing for the properties if the inputs. Hopefully some edifying...I hope you enjoy it!
The days get harder as they progress, and later days often require either improved algorithms or optimizing for the properties if the inputs. Hopefully some edifying challenges await!
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Comment on Day 3: Lobby in ~comp.advent_of_code
scarecrw LinkBit of a better day, as I guessed Part 2 so was already planning out the algorithm. My first thought was a DP solution (which napkin-math suggests might have worked?), but figured out a better...Bit of a better day, as I guessed Part 2 so was already planning out the algorithm. My first thought was a DP solution (which napkin-math suggests might have worked?), but figured out a better approach instead. Went back and refactored to add a couple new utilities and make the main solver tail-recursive.
I got spooked at first thinking it might be 2D arrays and realized I'll need to read up to figure out how best to handle that, as it's sure to be coming in the next few days.
Prolog Solution
:- ['src/util.pl']. max_batteries(N, Batteries, Joltage):- max_batteries(N, Batteries, 0, Joltage). max_batteries(0, _, Acc, Acc). max_batteries(N, Batteries, Acc, Joltage):- length(Batteries, L), FrontLength is L - N + 1, take(FrontLength, Batteries, Front), max_list(Front, MaxDigit), nth1(MaxIndex, Front, MaxDigit), drop(MaxIndex, Batteries, Rest), succ(N1, N), Acc1 is Acc + 10 ^ N1 * MaxDigit, max_batteries(N1, Rest, Acc1, Joltage). string_to_digits(String, Digits):- string_chars(String, DigitChars), maplist(char_code, DigitChars, Codes), maplist(plus(-48), Codes, Digits). main:- Filename = 'inputs/day03.txt', read_file_to_strings(Filename, BankStrings), maplist(string_to_digits, BankStrings, Banks), maplist(max_batteries(2), Banks, Joltages), sum_list(Joltages, Result1), write("Part 1: "), write(Result1), nl, maplist(max_batteries(12), Banks, Joltages2), sum_list(Joltages2, Result2), write("Part 2: "), write(Result2), nl, halt. :- initialization(main). -
Comment on Day 2: Gift Shop in ~comp.advent_of_code
scarecrw LinkBrute-forced it again, but learned a lot in doing so! Had one of my first "aha!" moments in using string_concat/3 backwards to both check if one string was a prefix of another and find the suffix...Brute-forced it again, but learned a lot in doing so!
Had one of my first "aha!" moments in using
string_concat/3backwards to both check if one string was a prefix of another and find the suffix that matched. No idea if it's the most efficient approach, but super neat!Prolog Solution
parse_range(RangeString, Range):- split_string(RangeString, "-", "", RangeStrings), maplist(number_string, Range, RangeStrings). find_invalids(IsInvalid, [RangeStart, RangeEnd], Invalids):- numlist(RangeStart, RangeEnd, Nums), include(IsInvalid, Nums, Invalids). is_invalid_1(Num):- number_string(Num, NumString), string_length(NumString, L), PartLength is div(L, 2), sub_string(NumString, 0, PartLength, PartLength, Left), sub_string(NumString, PartLength, PartLength, 0, Right), Left == Right. is_invalid_2(Num):- number_string(Num, NumString), string_length(NumString, L), between(2, L, NumParts), 0 is mod(L, NumParts), Before is div(L, NumParts), sub_string(NumString, 0, Before, _, Part), string_repeat(Part, NumString). string_repeat(_, ""). string_repeat(Part, String):- string_concat(Part, Rest, String), string_repeat(Part, Rest). main:- Filename = 'inputs/day02.txt', read_file_to_string(Filename, Input, []), split_string(Input, ",", "", RangeStrings), maplist(parse_range, RangeStrings, Ranges), maplist(find_invalids(is_invalid_1), Ranges, Invalids), maplist(sum_list, Invalids, InvalidSums), sum_list(InvalidSums, Result1), write("Part 1: "), write(Result1), nl, maplist(find_invalids(is_invalid_2), Ranges, Invalids2), maplist(sum_list, Invalids2, InvalidSums2), sum_list(InvalidSums2, Result2), write("Part 2: "), write(Result2), nl, halt. :- initialization(main).I made a note to learn about records, as right now I'm just using lists for everything.
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Comment on Day 1: Secret Entrance in ~comp.advent_of_code
scarecrw Link ParentThe language looks cool, but that website is phenomenal! I want every site for a language to be as simple and organized as this. Exactly the information I want without any extras in the way. I...The language looks cool, but that website is phenomenal! I want every site for a language to be as simple and organized as this. Exactly the information I want without any extras in the way.
I have to ask based on the username, is this a language you're connected to or just a happy coincidence?
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Comment on Day 1: Secret Entrance in ~comp.advent_of_code
scarecrw Link ParentLooks great! If you want a tip, it's often preferred to use the with syntax for file access, which ensures file closing even with exceptions. So instead of: file = open(filename, 'r') # ...code......Looks great!
If you want a tip, it's often preferred to use the
withsyntax for file access, which ensures file closing even with exceptions.So instead of:
file = open(filename, 'r') # ...code... file.close()you can use:
with open(filename, 'r') as file: # ...code... -
Comment on Day 1: Secret Entrance in ~comp.advent_of_code
scarecrw LinkOpted to try Prolog for this year. I don't have a clue what I'm doing, and may have bitten off more than I can chew, but I'm loving it so far! Day 1 Prolog Solution Spoilers Originally tried to do...Opted to try Prolog for this year. I don't have a clue what I'm doing, and may have bitten off more than I can chew, but I'm loving it so far!
Spoilers
Originally tried to do part 2 without the full expansion, as it worked almost perfectly with divmod, but gave up after a few frustrating issues and just went the naive route. The style is still pretty imperative, so I'm hoping on future days to try and understand more of the idiomatic approaches.
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Comment on Advent of Code starts tomorrow/tonight! Are you participating? Do you have any specific plans for this year? in ~comp.advent_of_code
scarecrw LinkI usually run a mini competition at work for AoC, but opted not to this year. We never had much participation, and there was some amount of unhealthy competition at play (the department includes...I usually run a mini competition at work for AoC, but opted not to this year. We never had much participation, and there was some amount of unhealthy competition at play (the department includes people with a wide variety of technical backgrounds, so the "difficulty" differences made it awkward). I'm somewhat disappointed not to be running it, but also excited to just be solving for myself.
I've tried to do a new language each year, and have left it to the last minute to decide. The last few years I did Rust, Haskell, and Smalltalk, all of which were great fun. With the shortened version this year, I'm thinking of going for something a bit more familiar, either a language I've touched a bit in the past (OCaml or Lua) or something more mainstream (Go or Scala). If anyone has any interesting suggestions, let me know!
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Advent of Code starts tomorrow/tonight! Are you participating? Do you have any specific plans for this year?
With Advent of Code upon us, I wanted to check out how everyone is planning on participating. If you hadn't heard, this year has been shortened to 12 days along with the removal of the global...
With Advent of Code upon us, I wanted to check out how everyone is planning on participating. If you hadn't heard, this year has been shortened to 12 days along with the removal of the global leaderboard.
- Any changes to how you'll approach this year based on the updated format?
- Are you using an interesting language/approach?
- Any goals you're setting for yourself?
I'm a sucker for puzzles in general, but I also love hearing about everyone else's experiences, so I'm excited to hear what y'all are looking forward to!
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Comment on PIGS, an opinionated unmarketable personal calculator in ~creative
scarecrw LinkThanks for sharing! I tried it out when you posted in the other thread but couldn't get the full picture without seeing the device. I never went down the RPN rabbit hole myself, but, working with...Thanks for sharing! I tried it out when you posted in the other thread but couldn't get the full picture without seeing the device.
I never went down the RPN rabbit hole myself, but, working with kids, their inability to understand parentheses and operator precedence does make me long for a world where RPN won out. I'm really curious how they'd take to the percent calculation tool, as I think seeing the numbers scroll together provides a more visceral understanding.
Also, mmmm that sound! You can tell how good the math is by the clickety-clack.
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Comment on Introducing Kagi News in ~tech
scarecrw Link ParentI've been disappointed in the amount of detail that's missing. I understand it's a summary, but even in the brief overview there's a lot of repeated information which takes up space when there...I've been disappointed in the amount of detail that's missing. I understand it's a summary, but even in the brief overview there's a lot of repeated information which takes up space when there would be better questions to ask/answer. For example, here's the same information 3 times from today's summary about the World Series game:
Some Canadian fans expressed frustration after singer Rufus Wainwright altered parts of O Canada during a recent anthem performance, prompting discussion online and in news coverage
Canadian singer Chantal Kreviazuk changed a line of the English lyrics at a February event, an act that received attention when Rufus Wainwright made similar tweaks later in the World Series
Singer Chantal Kreviazuk previously altered the English lyrics of O Canada at a February game, drawing public attention before Rufus Wainwright's more recent anthem variation
On the positive side, I have appreciated the limiting to only a finite set of articles.
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Comment on Upgrade desktop to win11 when hardware isn’t supported? in ~tech
scarecrw LinkIt's been long enough that I don't remember the details of installation (I believe it was just booting from a flash drive and doing a registry edit, this guide looks close to what I did), but I've...It's been long enough that I don't remember the details of installation (I believe it was just booting from a flash drive and doing a registry edit, this guide looks close to what I did), but I've been running Windows 11 without TPM with zero issues.
I can't speak to CPU or RAM requirements, though.
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Comment on Eq in ~music
scarecrw LinkAbsolutely love Posy's videos! Just a treat for your eyes, ears, and brain. I'm not sure if this is an existing youtube sub-genre, but I love the video idea of taking quality measurement devices...Absolutely love Posy's videos! Just a treat for your eyes, ears, and brain.
I'm not sure if this is an existing youtube sub-genre, but I love the video idea of taking quality measurement devices (and techniques) and just measuring the things around us. Especially for someone with such an extensive collection for comparison, it provides great insight into something I personally would never have otherwise given much thought.
Catching up on the last couple of days. This one went alright, though I was just lazy and figured at ~500 points I could probably get away with an n^3 solution. I believe I could get it to n^2logn without too much trouble if I had some more powerful data structures, but I already felt like a cheated on day 8 already by using a pre-made union-find.
Prolog Solution