{"person_view":{"person":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"counts":{"person_id":4299,"post_count":30,"comment_count":688},"is_admin":false},"site":{"id":27,"name":"sh.itjust.works","sidebar":"**Useful Links** \n* **[Lemmy Getting Started Guide](https://sh.itjust.works/post/24928)** \n* [Official Lemmy Support](https://sh.itjust.works/c/lemmy_support@lemmy.ml)\n* [Search communities across all lemmy instance](https://lemmyverse.net/communities)\n* sh.itjust.works meta discussion community: [!main@sh.itjust.works](https://sh.itjust.works/c/main) \n* sh.itjust.works Matrix chat: [https://matrix.to/#/#sh.itjust.works:matrix.org](https://matrix.to/#/#sh.itjust.works:matrix.org)\n\n**Donations** \n[![Ko-Fi](https://img.shields.io/badge/KoFi_Donate-SJW-red?style=flat-square&logo=kofi&color=red)](https://ko-fi.com/shitjustworks) \n[![Liberapay](https://img.shields.io/liberapay/patrons/sh.itjust.works?style=flat-square&logo=liberapay)](https://liberapay.com/sh.itjust.works)\n\n**Rules:**\n\n- Be respectful. 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Tout le monde doit se sentir le bienvenu ici.\n- Pas de bigoterie - y compris le racisme, le sexisme, le capacitisme, l'homophobie, la transphobie ou la xénophobie.\n- Pas de publicités / Pas de spam.\n- Pas de pornographie.\n\n![Fediseer](https://fediseer.com/api/v1/badges/guarantees/sh.itjust.works.svg) \n[![Fediseer](https://fediseer.com/api/v1/badges/endorsements/sh.itjust.works.svg)](https://gui.fediseer.com/instances/detail/sh.itjust.works) \n[![Matrix](https://img.shields.io/matrix/sh.itjust.works%3Amatrix.org?logo=matrix&%3Blabel=sh.itjust.works+Chat&%3Blink=https%3A%2F%2Fmatrix.to%2F%23%2F%23sh.itjust.works%3Amatrix.org)](https://matrix.to/#/#sh.itjust.works:matrix.org)\n\n**Other UI options (more to come)**\n- https://oldsh.itjust.works/\n- https://tesh.itjust.works/\n\n**Monitoring Services** \n- [lemmy-meter.info](https://lemmy-meter.info/d/GeoFE5WIz/instance-health-breakdown?var-lemmy_instance=sh.itjust.works&%3BorgId=1&%3Brefresh=1m)","published":"2023-06-29T05:12:51.524275Z","updated":"2025-06-03T21:08:17.748766Z","icon":"https://sh.itjust.works/pictrs/image/fb4c11a2-f533-4b0b-8f74-466132d93c72.webp","banner":"https://sh.itjust.works/pictrs/image/eca619a9-3d71-4804-9ba8-ad78327c58dd.webp","description":"A bilingual (EN/FR) general-purpose instance located in eastern Canada! Powered by 99% renewable energy! Everyone is welcome eh.","actor_id":"https://sh.itjust.works/","last_refreshed_at":"2025-07-05T00:50:44.965443Z","inbox_url":"https://sh.itjust.works/inbox","public_key":"-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA0BVqF6J7jTr5HyrBDpjS\nqponeT9fOvTlok+4JTBYSmrOsARSIVIlA2kx0w9mVW3hzKPzFTKTOqB2yREoZAqp\n6nUtDMW0xofCYj6Ilpw+jMopCovFMrUTOOe9JHmQtV+ShiOw5xXiGVbz1MS6+yqz\n3YVJ5cphiHMbQhziVJtdDSYNkOmKmgdSdjV0oSYRS52IxXjpz+PEvCREMjTmJlvm\nEGXbBxBbZ4KsoXhskBSUdvH6OZTPTcJV1u7lsH5fBjhQiuH+oipuASasfIzhm5HM\nh/G6nbdn6JweaBkLnQZZ8jvjLrUvRAf2Sm1rgYa1rmIQyCC4rk+fY9cWZzYT1npf\nFQIDAQAB\n-----END PUBLIC KEY-----\n","instance_id":32},"comments":[{"comment":{"id":13451082,"creator_id":4299,"post_id":16161763,"content":"Oh, don't get me wrong. Chrome and derivates are also terrible for spying on your every click. And unless it's a de-Googled chromium fork it absolutely still phones home to Google. Not quite as much as chrome, but still quite a bit.","removed":false,"published":"2024-12-18T08:57:20.904940Z","updated":"2024-12-18T10:12:00.589251Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15621047","local":false,"path":"0.13372833.13376479.13411565.13419191.13427087.13442379.13448913.13451082","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":16161763,"name":"Microsoft Recall screenshots credit cards and Social Security numbers, even with the \"sensitive information\" filter enabled","url":"https://www.tomshardware.com/software/windows/microsoft-recall-screenshots-credit-cards-and-social-security-numbers-even-with-the-sensitive-information-filter-enabled","creator_id":580,"community_id":252,"removed":false,"locked":false,"published":"2024-12-13T17:20:03.998201Z","deleted":false,"nsfw":false,"embed_title":"Microsoft Recall screenshots credit cards and Social Security numbers, even with the \"sensitive information\" filter enabled","embed_description":"Despite promising to filter personal data out, Recall still captures it.","thumbnail_url":"https://lemmy.ml/api/v3/image_proxy?url=https%3A%2F%2Fcdn.mos.cms.futurecdn.net%2F975UqEyQpEE6RNxsQCVvXL-1200-80.jpg","ap_id":"https://lemmy.ml/post/23543031","local":false,"language_id":37,"featured_community":false,"featured_local":false},"community":{"id":252,"name":"privacy","title":"Privacy","description":"# A place to discuss privacy and freedom in the digital world.\n\nPrivacy has become a very important issue in modern society, with companies and governments constantly abusing their power, more and more people are waking up to the importance of digital privacy. \n\nIn this community everyone is welcome to post links and discuss topics related to privacy.\n\n### Some Rules\n\n - Posting a link to a website containing tracking isn't great, if contents of the website are behind a paywall maybe copy them into the post\n - Don't promote proprietary software\n - Try to keep things on topic\n - If you have a question, please try searching for previous discussions, maybe it has already been answered\n - Reposts are fine, but should have at least a couple of weeks in between so that the post can reach a new audience\n - Be nice :)\n\n### Related communities\n\n- [Lemmy.ml libre_culture](https://lemmy.ml/c/libre_culture)\n- [Lemmy.ml privatelife](https://lemmy.ml/c/privatelife)\n- [Lemmy.ml DeGoogle](https://lemmy.ml/c/degoogle)\n- [Lemmy.ca privacy](https://lemmy.ca/c/privacy)\n\nmuch thanks to @gary_host_laptop for the logo design :)","removed":false,"published":"2019-11-15T23:50:53.712299Z","updated":"2024-11-22T21:30:19.947538Z","deleted":false,"nsfw":false,"actor_id":"https://lemmy.ml/c/privacy","local":false,"icon":"https://lemmy.ml/pictrs/image/h1ChnLuBHr.png","banner":"https://lemmy.ml/pictrs/image/DBjcqOW9ds.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":16,"visibility":"Public"},"counts":{"comment_id":13451082,"score":1,"upvotes":1,"downvotes":0,"published":"2024-12-18T08:57:20.904940Z","child_count":1},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13442379,"creator_id":4299,"post_id":16161763,"content":"Except it kinda does. It reinforces the dominant position Chrome has. A browser mono-culture, if you will. Google doesn't need to go through proper channels to establish a new standard if they can just set the de-facto-standard by supporting or, maybe more important, not supporting something in Chrome. And since Manifest v3 ad-blockers and other content filters are severely hampered, which only serves Google's ad-revenue but also hinders accessibility extensions. Mono-cultures just aren't healthy.","removed":false,"published":"2024-12-17T21:48:18.750356Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15613893","local":false,"path":"0.13372833.13376479.13411565.13419191.13427087.13442379","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":16161763,"name":"Microsoft Recall screenshots credit cards and Social Security numbers, even with the \"sensitive information\" filter enabled","url":"https://www.tomshardware.com/software/windows/microsoft-recall-screenshots-credit-cards-and-social-security-numbers-even-with-the-sensitive-information-filter-enabled","creator_id":580,"community_id":252,"removed":false,"locked":false,"published":"2024-12-13T17:20:03.998201Z","deleted":false,"nsfw":false,"embed_title":"Microsoft Recall screenshots credit cards and Social Security numbers, even with the \"sensitive information\" filter enabled","embed_description":"Despite promising to filter personal data out, Recall still captures it.","thumbnail_url":"https://lemmy.ml/api/v3/image_proxy?url=https%3A%2F%2Fcdn.mos.cms.futurecdn.net%2F975UqEyQpEE6RNxsQCVvXL-1200-80.jpg","ap_id":"https://lemmy.ml/post/23543031","local":false,"language_id":37,"featured_community":false,"featured_local":false},"community":{"id":252,"name":"privacy","title":"Privacy","description":"# A place to discuss privacy and freedom in the digital world.\n\nPrivacy has become a very important issue in modern society, with companies and governments constantly abusing their power, more and more people are waking up to the importance of digital privacy. \n\nIn this community everyone is welcome to post links and discuss topics related to privacy.\n\n### Some Rules\n\n - Posting a link to a website containing tracking isn't great, if contents of the website are behind a paywall maybe copy them into the post\n - Don't promote proprietary software\n - Try to keep things on topic\n - If you have a question, please try searching for previous discussions, maybe it has already been answered\n - Reposts are fine, but should have at least a couple of weeks in between so that the post can reach a new audience\n - Be nice :)\n\n### Related communities\n\n- [Lemmy.ml libre_culture](https://lemmy.ml/c/libre_culture)\n- [Lemmy.ml privatelife](https://lemmy.ml/c/privatelife)\n- [Lemmy.ml DeGoogle](https://lemmy.ml/c/degoogle)\n- [Lemmy.ca privacy](https://lemmy.ca/c/privacy)\n\nmuch thanks to @gary_host_laptop for the logo design :)","removed":false,"published":"2019-11-15T23:50:53.712299Z","updated":"2024-11-22T21:30:19.947538Z","deleted":false,"nsfw":false,"actor_id":"https://lemmy.ml/c/privacy","local":false,"icon":"https://lemmy.ml/pictrs/image/h1ChnLuBHr.png","banner":"https://lemmy.ml/pictrs/image/DBjcqOW9ds.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":16,"visibility":"Public"},"counts":{"comment_id":13442379,"score":1,"upvotes":1,"downvotes":0,"published":"2024-12-17T21:48:18.750356Z","child_count":3},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13419191,"creator_id":4299,"post_id":16161763,"content":"> Also I think most people do change there default browser but they change it to Chrome ):\n\nThey don't need to change it _to_ chrome, they're already using it. Every browser except for Firefox, with its derivatives, and Safari are Chrome. Plus a few more esoteric choices that are nowhere near daily-driver ready.","removed":false,"published":"2024-12-16T19:25:59.412606Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15594475","local":false,"path":"0.13372833.13376479.13411565.13419191","distinguished":false,"language_id":37},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":16161763,"name":"Microsoft Recall screenshots credit cards and Social Security numbers, even with the \"sensitive information\" filter enabled","url":"https://www.tomshardware.com/software/windows/microsoft-recall-screenshots-credit-cards-and-social-security-numbers-even-with-the-sensitive-information-filter-enabled","creator_id":580,"community_id":252,"removed":false,"locked":false,"published":"2024-12-13T17:20:03.998201Z","deleted":false,"nsfw":false,"embed_title":"Microsoft Recall screenshots credit cards and Social Security numbers, even with the \"sensitive information\" filter enabled","embed_description":"Despite promising to filter personal data out, Recall still captures it.","thumbnail_url":"https://lemmy.ml/api/v3/image_proxy?url=https%3A%2F%2Fcdn.mos.cms.futurecdn.net%2F975UqEyQpEE6RNxsQCVvXL-1200-80.jpg","ap_id":"https://lemmy.ml/post/23543031","local":false,"language_id":37,"featured_community":false,"featured_local":false},"community":{"id":252,"name":"privacy","title":"Privacy","description":"# A place to discuss privacy and freedom in the digital world.\n\nPrivacy has become a very important issue in modern society, with companies and governments constantly abusing their power, more and more people are waking up to the importance of digital privacy. \n\nIn this community everyone is welcome to post links and discuss topics related to privacy.\n\n### Some Rules\n\n - Posting a link to a website containing tracking isn't great, if contents of the website are behind a paywall maybe copy them into the post\n - Don't promote proprietary software\n - Try to keep things on topic\n - If you have a question, please try searching for previous discussions, maybe it has already been answered\n - Reposts are fine, but should have at least a couple of weeks in between so that the post can reach a new audience\n - Be nice :)\n\n### Related communities\n\n- [Lemmy.ml libre_culture](https://lemmy.ml/c/libre_culture)\n- [Lemmy.ml privatelife](https://lemmy.ml/c/privatelife)\n- [Lemmy.ml DeGoogle](https://lemmy.ml/c/degoogle)\n- [Lemmy.ca privacy](https://lemmy.ca/c/privacy)\n\nmuch thanks to @gary_host_laptop for the logo design :)","removed":false,"published":"2019-11-15T23:50:53.712299Z","updated":"2024-11-22T21:30:19.947538Z","deleted":false,"nsfw":false,"actor_id":"https://lemmy.ml/c/privacy","local":false,"icon":"https://lemmy.ml/pictrs/image/h1ChnLuBHr.png","banner":"https://lemmy.ml/pictrs/image/DBjcqOW9ds.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":16,"visibility":"Public"},"counts":{"comment_id":13419191,"score":1,"upvotes":1,"downvotes":0,"published":"2024-12-16T19:25:59.412606Z","child_count":5},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13376479,"creator_id":4299,"post_id":16161763,"content":"Yes, but I think we're talking about a very small percentage. The vast majority will just go \"man, that sucks\" and continue using it because they're too lazy to leave their comfort zone. Most users don't even change the default browser, which is arguably one of the easiest things to change. ","removed":false,"published":"2024-12-14T11:48:22.780526Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15557836","local":false,"path":"0.13372833.13376479","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":16161763,"name":"Microsoft Recall screenshots credit cards and Social Security numbers, even with the \"sensitive information\" filter enabled","url":"https://www.tomshardware.com/software/windows/microsoft-recall-screenshots-credit-cards-and-social-security-numbers-even-with-the-sensitive-information-filter-enabled","creator_id":580,"community_id":252,"removed":false,"locked":false,"published":"2024-12-13T17:20:03.998201Z","deleted":false,"nsfw":false,"embed_title":"Microsoft Recall screenshots credit cards and Social Security numbers, even with the \"sensitive information\" filter enabled","embed_description":"Despite promising to filter personal data out, Recall still captures it.","thumbnail_url":"https://lemmy.ml/api/v3/image_proxy?url=https%3A%2F%2Fcdn.mos.cms.futurecdn.net%2F975UqEyQpEE6RNxsQCVvXL-1200-80.jpg","ap_id":"https://lemmy.ml/post/23543031","local":false,"language_id":37,"featured_community":false,"featured_local":false},"community":{"id":252,"name":"privacy","title":"Privacy","description":"# A place to discuss privacy and freedom in the digital world.\n\nPrivacy has become a very important issue in modern society, with companies and governments constantly abusing their power, more and more people are waking up to the importance of digital privacy. \n\nIn this community everyone is welcome to post links and discuss topics related to privacy.\n\n### Some Rules\n\n - Posting a link to a website containing tracking isn't great, if contents of the website are behind a paywall maybe copy them into the post\n - Don't promote proprietary software\n - Try to keep things on topic\n - If you have a question, please try searching for previous discussions, maybe it has already been answered\n - Reposts are fine, but should have at least a couple of weeks in between so that the post can reach a new audience\n - Be nice :)\n\n### Related communities\n\n- [Lemmy.ml libre_culture](https://lemmy.ml/c/libre_culture)\n- [Lemmy.ml privatelife](https://lemmy.ml/c/privatelife)\n- [Lemmy.ml DeGoogle](https://lemmy.ml/c/degoogle)\n- [Lemmy.ca privacy](https://lemmy.ca/c/privacy)\n\nmuch thanks to @gary_host_laptop for the logo design :)","removed":false,"published":"2019-11-15T23:50:53.712299Z","updated":"2024-11-22T21:30:19.947538Z","deleted":false,"nsfw":false,"actor_id":"https://lemmy.ml/c/privacy","local":false,"icon":"https://lemmy.ml/pictrs/image/h1ChnLuBHr.png","banner":"https://lemmy.ml/pictrs/image/DBjcqOW9ds.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":16,"visibility":"Public"},"counts":{"comment_id":13376479,"score":9,"upvotes":9,"downvotes":0,"published":"2024-12-14T11:48:22.780526Z","child_count":7},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13260952,"creator_id":4299,"post_id":15906672,"content":"Shoot a ray to the right, if and when it collides, shoot a ray to the right, … \nYou know, recursion. ","removed":false,"published":"2024-12-08T21:54:49.440927Z","updated":"2024-12-08T21:55:09.730312Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15459074","local":false,"path":"0.13246773.13248122.13256490.13256787.13260833.13260952","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15906672,"name":"Stuck on day 6, part 2","body":"I'm not looking for a solution or even code, just a hint. Here's what I currently do: \n1. Add the current position and heading to the recorded path\n2. Check if turning right would lead back onto the recorded path in the same direction we walked it before\n3. Check if the next field is obstructed\n 1. If so, turn right\n 2. Repeat until no longer blocked\n4. Update current position\n\nThis approach works fine for the unit test, but yields a result too low for the puzzle input. I tried adding recursion to the party check, but even 20 levels of recursion didn't sufficiently increase the amount of options found, suggesting I'm missing a mechanism to identify them.\n\nAny clues?\n\nCurrent state of affairs:\n```python\nfrom math import sumprod\nfrom operator import add\nfrom pathlib import Path\n\n\ndef parse_input(input: str) -> list[list[int]]:\n return input.strip().splitlines()\n\n\ndef find_guard(world: list[list[int]]) -> tuple[int]:\n for y, line in enumerate(world):\n x = line.find(\"^\")\n if x > -1:\n return (y, x)\n return (-1, -1) # No guard\n\n\ndef turn(heading: tuple[int]) -> tuple[int]:\n mat = [(0, 1), (-1, 0)]\n return tuple([sumprod(col, heading) for col in mat])\n\n\ndef step(pos: tuple[int], heading: tuple[int]) -> tuple[int]:\n return tuple(map(add, pos, heading))\n\n\ndef is_blocked(world: list[list[str]], guard: tuple[int], heading: tuple[int]) -> bool:\n pos = step(guard, heading)\n try:\n return world[pos[0]][pos[1]] == \"#\"\n except IndexError:\n return False\n\n\ndef cast_ray(\n world: list[list[int]], start: tuple[int], heading: tuple[int]\n) -> list[tuple[int]]:\n pos = step(start, heading)\n ray = []\n try:\n while world[pos[0]][pos[1]] != \"#\":\n ray.append(pos)\n pos = step(pos, heading)\n except IndexError:\n # Left the world\n ...\n return ray\n\n\ndef part_one(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n while is_blocked(world, guard, heading):\n heading = turn(heading)\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return sum([line.count(\"X\") for line in world])\n\n\ndef part_two(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n path = {}\n options = 0\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n path.setdefault(guard, []).append(heading)\n turned = turn(heading)\n if turned in path.get(guard, []) or turned in [\n d\n for p in set(cast_ray(world, guard, turned)).intersection(set(path.keys()))\n for d in path[p]\n ]:\n # Crossing previous path and turning would cause us to retrace our steps\n # or turning would lead us back into our previous path\n options += 1\n while is_blocked(world, guard, heading):\n heading = turned\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return options\n\n\nif __name__ == \"__main__\":\n input = Path(\"input\").read_text(\"utf-8\")\n print(part_one(input))\n print(part_two(input))\n```","creator_id":4299,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-06T13:43:03.452256Z","updated":"2024-12-06T15:28:28.351378Z","deleted":false,"nsfw":false,"ap_id":"https://sh.itjust.works/post/29102605","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13260952,"score":0,"upvotes":1,"downvotes":1,"published":"2024-12-08T21:54:49.440927Z","child_count":0},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13256787,"creator_id":4299,"post_id":15906672,"content":"That's what I meant with the second part of my reply. With a recursion depth of at least 4 it'll detect the option for a loop at the location of the `^`. ","removed":false,"published":"2024-12-08T17:59:32.067015Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15455795","local":false,"path":"0.13246773.13248122.13256490.13256787","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15906672,"name":"Stuck on day 6, part 2","body":"I'm not looking for a solution or even code, just a hint. Here's what I currently do: \n1. Add the current position and heading to the recorded path\n2. Check if turning right would lead back onto the recorded path in the same direction we walked it before\n3. Check if the next field is obstructed\n 1. If so, turn right\n 2. Repeat until no longer blocked\n4. Update current position\n\nThis approach works fine for the unit test, but yields a result too low for the puzzle input. I tried adding recursion to the party check, but even 20 levels of recursion didn't sufficiently increase the amount of options found, suggesting I'm missing a mechanism to identify them.\n\nAny clues?\n\nCurrent state of affairs:\n```python\nfrom math import sumprod\nfrom operator import add\nfrom pathlib import Path\n\n\ndef parse_input(input: str) -> list[list[int]]:\n return input.strip().splitlines()\n\n\ndef find_guard(world: list[list[int]]) -> tuple[int]:\n for y, line in enumerate(world):\n x = line.find(\"^\")\n if x > -1:\n return (y, x)\n return (-1, -1) # No guard\n\n\ndef turn(heading: tuple[int]) -> tuple[int]:\n mat = [(0, 1), (-1, 0)]\n return tuple([sumprod(col, heading) for col in mat])\n\n\ndef step(pos: tuple[int], heading: tuple[int]) -> tuple[int]:\n return tuple(map(add, pos, heading))\n\n\ndef is_blocked(world: list[list[str]], guard: tuple[int], heading: tuple[int]) -> bool:\n pos = step(guard, heading)\n try:\n return world[pos[0]][pos[1]] == \"#\"\n except IndexError:\n return False\n\n\ndef cast_ray(\n world: list[list[int]], start: tuple[int], heading: tuple[int]\n) -> list[tuple[int]]:\n pos = step(start, heading)\n ray = []\n try:\n while world[pos[0]][pos[1]] != \"#\":\n ray.append(pos)\n pos = step(pos, heading)\n except IndexError:\n # Left the world\n ...\n return ray\n\n\ndef part_one(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n while is_blocked(world, guard, heading):\n heading = turn(heading)\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return sum([line.count(\"X\") for line in world])\n\n\ndef part_two(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n path = {}\n options = 0\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n path.setdefault(guard, []).append(heading)\n turned = turn(heading)\n if turned in path.get(guard, []) or turned in [\n d\n for p in set(cast_ray(world, guard, turned)).intersection(set(path.keys()))\n for d in path[p]\n ]:\n # Crossing previous path and turning would cause us to retrace our steps\n # or turning would lead us back into our previous path\n options += 1\n while is_blocked(world, guard, heading):\n heading = turned\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return options\n\n\nif __name__ == \"__main__\":\n input = Path(\"input\").read_text(\"utf-8\")\n print(part_one(input))\n print(part_two(input))\n```","creator_id":4299,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-06T13:43:03.452256Z","updated":"2024-12-06T15:28:28.351378Z","deleted":false,"nsfw":false,"ap_id":"https://sh.itjust.works/post/29102605","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13256787,"score":1,"upvotes":1,"downvotes":0,"published":"2024-12-08T17:59:32.067015Z","child_count":2},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13248122,"creator_id":4299,"post_id":15906672,"content":"I'm only casting a ray to detect where turning right *now* would lead. So to stick with your example:\n```\n.O..\n-^+#\n#++.\n..#.\n```\nIf the guard had come from the left and run this little loop I'd detect this location to place an obstacle. \nAlternatively, if I switch back to recursive rays, I'd detect this location a little later:\n```\n.O..\n.^.#\n#|..\n.|#.\n```","removed":false,"published":"2024-12-08T08:08:20.104669Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15448669","local":false,"path":"0.13246773.13248122","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15906672,"name":"Stuck on day 6, part 2","body":"I'm not looking for a solution or even code, just a hint. Here's what I currently do: \n1. Add the current position and heading to the recorded path\n2. Check if turning right would lead back onto the recorded path in the same direction we walked it before\n3. Check if the next field is obstructed\n 1. If so, turn right\n 2. Repeat until no longer blocked\n4. Update current position\n\nThis approach works fine for the unit test, but yields a result too low for the puzzle input. I tried adding recursion to the party check, but even 20 levels of recursion didn't sufficiently increase the amount of options found, suggesting I'm missing a mechanism to identify them.\n\nAny clues?\n\nCurrent state of affairs:\n```python\nfrom math import sumprod\nfrom operator import add\nfrom pathlib import Path\n\n\ndef parse_input(input: str) -> list[list[int]]:\n return input.strip().splitlines()\n\n\ndef find_guard(world: list[list[int]]) -> tuple[int]:\n for y, line in enumerate(world):\n x = line.find(\"^\")\n if x > -1:\n return (y, x)\n return (-1, -1) # No guard\n\n\ndef turn(heading: tuple[int]) -> tuple[int]:\n mat = [(0, 1), (-1, 0)]\n return tuple([sumprod(col, heading) for col in mat])\n\n\ndef step(pos: tuple[int], heading: tuple[int]) -> tuple[int]:\n return tuple(map(add, pos, heading))\n\n\ndef is_blocked(world: list[list[str]], guard: tuple[int], heading: tuple[int]) -> bool:\n pos = step(guard, heading)\n try:\n return world[pos[0]][pos[1]] == \"#\"\n except IndexError:\n return False\n\n\ndef cast_ray(\n world: list[list[int]], start: tuple[int], heading: tuple[int]\n) -> list[tuple[int]]:\n pos = step(start, heading)\n ray = []\n try:\n while world[pos[0]][pos[1]] != \"#\":\n ray.append(pos)\n pos = step(pos, heading)\n except IndexError:\n # Left the world\n ...\n return ray\n\n\ndef part_one(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n while is_blocked(world, guard, heading):\n heading = turn(heading)\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return sum([line.count(\"X\") for line in world])\n\n\ndef part_two(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n path = {}\n options = 0\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n path.setdefault(guard, []).append(heading)\n turned = turn(heading)\n if turned in path.get(guard, []) or turned in [\n d\n for p in set(cast_ray(world, guard, turned)).intersection(set(path.keys()))\n for d in path[p]\n ]:\n # Crossing previous path and turning would cause us to retrace our steps\n # or turning would lead us back into our previous path\n options += 1\n while is_blocked(world, guard, heading):\n heading = turned\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return options\n\n\nif __name__ == \"__main__\":\n input = Path(\"input\").read_text(\"utf-8\")\n print(part_one(input))\n print(part_two(input))\n```","creator_id":4299,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-06T13:43:03.452256Z","updated":"2024-12-06T15:28:28.351378Z","deleted":false,"nsfw":false,"ap_id":"https://sh.itjust.works/post/29102605","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13248122,"score":1,"upvotes":1,"downvotes":0,"published":"2024-12-08T08:08:20.104669Z","child_count":4},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13205746,"creator_id":4299,"post_id":15906672,"content":"Done","removed":false,"published":"2024-12-06T15:28:55.535983Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15420012","local":false,"path":"0.13205612.13205746","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15906672,"name":"Stuck on day 6, part 2","body":"I'm not looking for a solution or even code, just a hint. Here's what I currently do: \n1. Add the current position and heading to the recorded path\n2. Check if turning right would lead back onto the recorded path in the same direction we walked it before\n3. Check if the next field is obstructed\n 1. If so, turn right\n 2. Repeat until no longer blocked\n4. Update current position\n\nThis approach works fine for the unit test, but yields a result too low for the puzzle input. I tried adding recursion to the party check, but even 20 levels of recursion didn't sufficiently increase the amount of options found, suggesting I'm missing a mechanism to identify them.\n\nAny clues?\n\nCurrent state of affairs:\n```python\nfrom math import sumprod\nfrom operator import add\nfrom pathlib import Path\n\n\ndef parse_input(input: str) -> list[list[int]]:\n return input.strip().splitlines()\n\n\ndef find_guard(world: list[list[int]]) -> tuple[int]:\n for y, line in enumerate(world):\n x = line.find(\"^\")\n if x > -1:\n return (y, x)\n return (-1, -1) # No guard\n\n\ndef turn(heading: tuple[int]) -> tuple[int]:\n mat = [(0, 1), (-1, 0)]\n return tuple([sumprod(col, heading) for col in mat])\n\n\ndef step(pos: tuple[int], heading: tuple[int]) -> tuple[int]:\n return tuple(map(add, pos, heading))\n\n\ndef is_blocked(world: list[list[str]], guard: tuple[int], heading: tuple[int]) -> bool:\n pos = step(guard, heading)\n try:\n return world[pos[0]][pos[1]] == \"#\"\n except IndexError:\n return False\n\n\ndef cast_ray(\n world: list[list[int]], start: tuple[int], heading: tuple[int]\n) -> list[tuple[int]]:\n pos = step(start, heading)\n ray = []\n try:\n while world[pos[0]][pos[1]] != \"#\":\n ray.append(pos)\n pos = step(pos, heading)\n except IndexError:\n # Left the world\n ...\n return ray\n\n\ndef part_one(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n while is_blocked(world, guard, heading):\n heading = turn(heading)\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return sum([line.count(\"X\") for line in world])\n\n\ndef part_two(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n path = {}\n options = 0\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n path.setdefault(guard, []).append(heading)\n turned = turn(heading)\n if turned in path.get(guard, []) or turned in [\n d\n for p in set(cast_ray(world, guard, turned)).intersection(set(path.keys()))\n for d in path[p]\n ]:\n # Crossing previous path and turning would cause us to retrace our steps\n # or turning would lead us back into our previous path\n options += 1\n while is_blocked(world, guard, heading):\n heading = turned\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return options\n\n\nif __name__ == \"__main__\":\n input = Path(\"input\").read_text(\"utf-8\")\n print(part_one(input))\n print(part_two(input))\n```","creator_id":4299,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-06T13:43:03.452256Z","updated":"2024-12-06T15:28:28.351378Z","deleted":false,"nsfw":false,"ap_id":"https://sh.itjust.works/post/29102605","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13205746,"score":2,"upvotes":2,"downvotes":0,"published":"2024-12-06T15:28:55.535983Z","child_count":0},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13205437,"creator_id":4299,"post_id":15906672,"content":"Yes. For every step I check if turning would lead me back onto my previous path, either because I'm crossing it or because walking that direction will eventually bring me back onto it, passing the obstacle that cause me to turn.","removed":false,"published":"2024-12-06T14:57:44.510104Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15419451","local":false,"path":"0.13204947.13205014.13205199.13205437","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15906672,"name":"Stuck on day 6, part 2","body":"I'm not looking for a solution or even code, just a hint. Here's what I currently do: \n1. Add the current position and heading to the recorded path\n2. Check if turning right would lead back onto the recorded path in the same direction we walked it before\n3. Check if the next field is obstructed\n 1. If so, turn right\n 2. Repeat until no longer blocked\n4. Update current position\n\nThis approach works fine for the unit test, but yields a result too low for the puzzle input. I tried adding recursion to the party check, but even 20 levels of recursion didn't sufficiently increase the amount of options found, suggesting I'm missing a mechanism to identify them.\n\nAny clues?\n\nCurrent state of affairs:\n```python\nfrom math import sumprod\nfrom operator import add\nfrom pathlib import Path\n\n\ndef parse_input(input: str) -> list[list[int]]:\n return input.strip().splitlines()\n\n\ndef find_guard(world: list[list[int]]) -> tuple[int]:\n for y, line in enumerate(world):\n x = line.find(\"^\")\n if x > -1:\n return (y, x)\n return (-1, -1) # No guard\n\n\ndef turn(heading: tuple[int]) -> tuple[int]:\n mat = [(0, 1), (-1, 0)]\n return tuple([sumprod(col, heading) for col in mat])\n\n\ndef step(pos: tuple[int], heading: tuple[int]) -> tuple[int]:\n return tuple(map(add, pos, heading))\n\n\ndef is_blocked(world: list[list[str]], guard: tuple[int], heading: tuple[int]) -> bool:\n pos = step(guard, heading)\n try:\n return world[pos[0]][pos[1]] == \"#\"\n except IndexError:\n return False\n\n\ndef cast_ray(\n world: list[list[int]], start: tuple[int], heading: tuple[int]\n) -> list[tuple[int]]:\n pos = step(start, heading)\n ray = []\n try:\n while world[pos[0]][pos[1]] != \"#\":\n ray.append(pos)\n pos = step(pos, heading)\n except IndexError:\n # Left the world\n ...\n return ray\n\n\ndef part_one(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n while is_blocked(world, guard, heading):\n heading = turn(heading)\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return sum([line.count(\"X\") for line in world])\n\n\ndef part_two(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n path = {}\n options = 0\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n path.setdefault(guard, []).append(heading)\n turned = turn(heading)\n if turned in path.get(guard, []) or turned in [\n d\n for p in set(cast_ray(world, guard, turned)).intersection(set(path.keys()))\n for d in path[p]\n ]:\n # Crossing previous path and turning would cause us to retrace our steps\n # or turning would lead us back into our previous path\n options += 1\n while is_blocked(world, guard, heading):\n heading = turned\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return options\n\n\nif __name__ == \"__main__\":\n input = Path(\"input\").read_text(\"utf-8\")\n print(part_one(input))\n print(part_two(input))\n```","creator_id":4299,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-06T13:43:03.452256Z","updated":"2024-12-06T15:28:28.351378Z","deleted":false,"nsfw":false,"ap_id":"https://sh.itjust.works/post/29102605","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13205437,"score":1,"upvotes":1,"downvotes":0,"published":"2024-12-06T14:57:44.510104Z","child_count":0},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13205370,"creator_id":4299,"post_id":15906672,"content":"> But if you move onto a location+heading that you traversed before, that is a loop.\n\nWhich is the express goal of part 2. \nConversely walking in the opposite direction would lead me right past any obstacle that cause me to turn. So it's not particularly useful. ","removed":false,"published":"2024-12-06T14:54:44.149829Z","updated":"2024-12-06T14:59:15.977218Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15419391","local":false,"path":"0.13205132.13205370","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15906672,"name":"Stuck on day 6, part 2","body":"I'm not looking for a solution or even code, just a hint. Here's what I currently do: \n1. Add the current position and heading to the recorded path\n2. Check if turning right would lead back onto the recorded path in the same direction we walked it before\n3. Check if the next field is obstructed\n 1. If so, turn right\n 2. Repeat until no longer blocked\n4. Update current position\n\nThis approach works fine for the unit test, but yields a result too low for the puzzle input. I tried adding recursion to the party check, but even 20 levels of recursion didn't sufficiently increase the amount of options found, suggesting I'm missing a mechanism to identify them.\n\nAny clues?\n\nCurrent state of affairs:\n```python\nfrom math import sumprod\nfrom operator import add\nfrom pathlib import Path\n\n\ndef parse_input(input: str) -> list[list[int]]:\n return input.strip().splitlines()\n\n\ndef find_guard(world: list[list[int]]) -> tuple[int]:\n for y, line in enumerate(world):\n x = line.find(\"^\")\n if x > -1:\n return (y, x)\n return (-1, -1) # No guard\n\n\ndef turn(heading: tuple[int]) -> tuple[int]:\n mat = [(0, 1), (-1, 0)]\n return tuple([sumprod(col, heading) for col in mat])\n\n\ndef step(pos: tuple[int], heading: tuple[int]) -> tuple[int]:\n return tuple(map(add, pos, heading))\n\n\ndef is_blocked(world: list[list[str]], guard: tuple[int], heading: tuple[int]) -> bool:\n pos = step(guard, heading)\n try:\n return world[pos[0]][pos[1]] == \"#\"\n except IndexError:\n return False\n\n\ndef cast_ray(\n world: list[list[int]], start: tuple[int], heading: tuple[int]\n) -> list[tuple[int]]:\n pos = step(start, heading)\n ray = []\n try:\n while world[pos[0]][pos[1]] != \"#\":\n ray.append(pos)\n pos = step(pos, heading)\n except IndexError:\n # Left the world\n ...\n return ray\n\n\ndef part_one(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n while is_blocked(world, guard, heading):\n heading = turn(heading)\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return sum([line.count(\"X\") for line in world])\n\n\ndef part_two(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n path = {}\n options = 0\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n path.setdefault(guard, []).append(heading)\n turned = turn(heading)\n if turned in path.get(guard, []) or turned in [\n d\n for p in set(cast_ray(world, guard, turned)).intersection(set(path.keys()))\n for d in path[p]\n ]:\n # Crossing previous path and turning would cause us to retrace our steps\n # or turning would lead us back into our previous path\n options += 1\n while is_blocked(world, guard, heading):\n heading = turned\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return options\n\n\nif __name__ == \"__main__\":\n input = Path(\"input\").read_text(\"utf-8\")\n print(part_one(input))\n print(part_two(input))\n```","creator_id":4299,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-06T13:43:03.452256Z","updated":"2024-12-06T15:28:28.351378Z","deleted":false,"nsfw":false,"ap_id":"https://sh.itjust.works/post/29102605","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13205370,"score":1,"upvotes":1,"downvotes":0,"published":"2024-12-06T14:54:44.149829Z","child_count":1},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13205014,"creator_id":4299,"post_id":15906672,"content":"It just keeps turning. See 3.2. Worst case is it has to turn twice and walk back where it came. ","removed":false,"published":"2024-12-06T14:31:33.329945Z","updated":"2024-12-06T14:35:39.633349Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15418988","local":false,"path":"0.13204947.13205014","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15906672,"name":"Stuck on day 6, part 2","body":"I'm not looking for a solution or even code, just a hint. Here's what I currently do: \n1. Add the current position and heading to the recorded path\n2. Check if turning right would lead back onto the recorded path in the same direction we walked it before\n3. Check if the next field is obstructed\n 1. If so, turn right\n 2. Repeat until no longer blocked\n4. Update current position\n\nThis approach works fine for the unit test, but yields a result too low for the puzzle input. I tried adding recursion to the party check, but even 20 levels of recursion didn't sufficiently increase the amount of options found, suggesting I'm missing a mechanism to identify them.\n\nAny clues?\n\nCurrent state of affairs:\n```python\nfrom math import sumprod\nfrom operator import add\nfrom pathlib import Path\n\n\ndef parse_input(input: str) -> list[list[int]]:\n return input.strip().splitlines()\n\n\ndef find_guard(world: list[list[int]]) -> tuple[int]:\n for y, line in enumerate(world):\n x = line.find(\"^\")\n if x > -1:\n return (y, x)\n return (-1, -1) # No guard\n\n\ndef turn(heading: tuple[int]) -> tuple[int]:\n mat = [(0, 1), (-1, 0)]\n return tuple([sumprod(col, heading) for col in mat])\n\n\ndef step(pos: tuple[int], heading: tuple[int]) -> tuple[int]:\n return tuple(map(add, pos, heading))\n\n\ndef is_blocked(world: list[list[str]], guard: tuple[int], heading: tuple[int]) -> bool:\n pos = step(guard, heading)\n try:\n return world[pos[0]][pos[1]] == \"#\"\n except IndexError:\n return False\n\n\ndef cast_ray(\n world: list[list[int]], start: tuple[int], heading: tuple[int]\n) -> list[tuple[int]]:\n pos = step(start, heading)\n ray = []\n try:\n while world[pos[0]][pos[1]] != \"#\":\n ray.append(pos)\n pos = step(pos, heading)\n except IndexError:\n # Left the world\n ...\n return ray\n\n\ndef part_one(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n while is_blocked(world, guard, heading):\n heading = turn(heading)\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return sum([line.count(\"X\") for line in world])\n\n\ndef part_two(input: str) -> int:\n world = parse_input(input)\n guard = find_guard(world)\n heading = (-1, 0)\n path = {}\n options = 0\n while (\n guard[0] >= 0\n and guard[0] < len(world)\n and guard[1] >= 0\n and guard[1] < len(world[guard[0]])\n ):\n path.setdefault(guard, []).append(heading)\n turned = turn(heading)\n if turned in path.get(guard, []) or turned in [\n d\n for p in set(cast_ray(world, guard, turned)).intersection(set(path.keys()))\n for d in path[p]\n ]:\n # Crossing previous path and turning would cause us to retrace our steps\n # or turning would lead us back into our previous path\n options += 1\n while is_blocked(world, guard, heading):\n heading = turned\n world[guard[0]] = f\"{world[guard[0]][:guard[1]]}X{world[guard[0]][guard[1]+1:]}\"\n guard = tuple(map(add, guard, heading))\n return options\n\n\nif __name__ == \"__main__\":\n input = Path(\"input\").read_text(\"utf-8\")\n print(part_one(input))\n print(part_two(input))\n```","creator_id":4299,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-06T13:43:03.452256Z","updated":"2024-12-06T15:28:28.351378Z","deleted":false,"nsfw":false,"ap_id":"https://sh.itjust.works/post/29102605","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13205014,"score":1,"upvotes":1,"downvotes":0,"published":"2024-12-06T14:31:33.329945Z","child_count":2},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13198121,"creator_id":4299,"post_id":15879764,"content":"\"Open source\" is still commonly used to mean FOSS. Source available software isn't common enough to have made its way into the broader vocabulary. ","removed":false,"published":"2024-12-06T06:14:54.908562Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15413518","local":false,"path":"0.13194913.13198121","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15879764,"name":"I answered: Why does \"open source\" matter?","body":"Nobody on my post [asking for controversial privacy topics](https://lemmy.ml/post/22764288) asked this question, but I feel I should cover it anyways. People sometimes assume that software is safe simply because it is open source. That is a misconception, and I would like to cover that in this post.\n\n# What does \"open source\" mean?\n\nWhen software is \"open source,\" it means that the developers have made the source code for the software public and allows anyone to help contribute to the code, or create their own versions of the software based on the source code. By contrast, proprietary software is software that has not made the source code visible to the public. There are similar terms to open source, such as \"source-available,\" \"open-core,\" and \"libre,\" which I won't cover in this post. For the sake of simplicity, any source-available software will be called \"open source,\" since the specifics don't quite matter for the majority of this post. \n\n# What are the benefits open source software?\n\nOpen source software provides many benefits over proprietary software:\n\n**Code auditing:** Because anyone can inspect the code, anybody can look for vulnerabilities or invasive code to make sure that the software is safe. With proprietary software, the developers would have to hire a third party auditor to inspect the code. That means you have to trust the auditor, and you have no way to verify first-hand that the code is safe. \n\n**Bug reporting:** While both open source and proprietary software have bug reporting systems, open source software tends to have more thorough and transparent bug reporting. Bug reports are generally on a public issue tracker such as GitHub, which can also help prevent duplicate bugs from being reported. Having these reports public also makes the next benefit easier:\n\n**Bug fixing:** Anyone can contribute to open source software, which means the workload is distributed. Instead of a small team of developers being the only ones working on the software, anyone can look at the public issues and code their own fixes for the software. \n\n**Resurrecting projects:** Both open source and proprietary software can one day stop being developed. Even big companies such as Spotify can [retire software](https://en.wikipedia.org/wiki/Car_Thing), which can lead to hardware devices becoming unusable or insecure. (The code for Car Thing has been [reconstructed](https://github.com/merlin04/superbird-webapp), by the way.) Open source projects that fall out of development can easily be forked and maintained by a new developer. It's rare to see proprietary software handed off to a new owner. \n\n**Accountability:** Open source projects hold the developers directly accountable for any vulnerabilities or invasive code, meaning the developer's interests are aligned with its users and not malicious purposes. This also incentivizes creating code without paywalls, since anyone could release a version of the code with the paid features \"unlocked\". \n\nHowever, even with all these benefits, open source software isn't perfect. \n\n# Why has proprietary software become so popular?\n\nSince ads and paywalls can generally be removed from open source software, it doesn't make it a very appealing choice to for-profit organizations. Generally, these organizations want to monetize and control their software, which means injecting ads, paywalls, and other invasive elements. This is done most easily if the software is proprietary.\n\nIt's also rare to see open source software becoming so popular, because generally open source software receives its funding from donations and doesn't have the budget to advertise the software. There are exceptions, such as [OBS Studio](https://obsproject.com/) or [Blender](https://www.blender.org/), which have mostly become the most popular software in their categories. \n\n# Is open source software safe?\n\nThere is another downside to open source software that many people don't talk about: it is much easier to exploit than proprietary software. Because all the source code is visible to the public, it makes it easy for malicious parties to craft vulnerabilities. Proprietary software is generally a stab in the dark until a vulnerability is found, since you can't see exactly how it was coded. \n\nSoftware being open source does mean that it becomes more likely to find and fix vulnerabilities, but being open source doesn't automatically make software safe. Which device do you think would be more likely to obtain a virus, a device running (stock) Android or a device running iOS? You're most likely more inclined to say the device running (stock) Android is more likely. Android at its core is [open source](https://source.android.com/). While correlation is not causation, and there are other factors at play, it's much easier for someone to try to craft a malicious app for Android than for iOS because of its open nature. \n\nProprietary software isn't automatically safe, either. It can be just as vulnerable as any other software. However, open source software has the potential to become much more secure than proprietary software, simply because more people can find and fix vulnerabilities. That's probably why Apple open sourced their [Private Cloud Compute](https://github.com/apple/security-pcc) code before launching a [bounty program](https://security.apple.com/blog/pcc-security-research/) for it. \n\nAnyone can code malicious open source software. It's riskier, since it's more likely to be noticed, but it's still possible. Microsoft could open source Windows one day, and it wouldn't make it any more safe until somebody identified and fixed the issues. Open source software doesn't automatically make something private or secure, but it does provide *integrity*, because the developer is showing that they will be accountable for any malicious or vulnerable code, and that anyone is free to look through the code. \n\n# Final notes\n\nI hope this gives you a better idea of what it actually means if something is open source. Even unsafe proprietary software can be run safely under the right conditions. If your threat model requires you to use as much open source software as possible, I made my own list of open source software called [Open Source Everything](https://github.com/An-anonymous-coder/Open-Source-Everything) that you can look through. I hope you enjoyed reading this!\n\n\\- The 8232 Project","creator_id":6855466,"community_id":252,"removed":false,"locked":false,"published":"2024-12-05T17:40:56.084856Z","deleted":false,"nsfw":false,"ap_id":"https://lemmy.ml/post/23254488","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":252,"name":"privacy","title":"Privacy","description":"# A place to discuss privacy and freedom in the digital world.\n\nPrivacy has become a very important issue in modern society, with companies and governments constantly abusing their power, more and more people are waking up to the importance of digital privacy. \n\nIn this community everyone is welcome to post links and discuss topics related to privacy.\n\n### Some Rules\n\n - Posting a link to a website containing tracking isn't great, if contents of the website are behind a paywall maybe copy them into the post\n - Don't promote proprietary software\n - Try to keep things on topic\n - If you have a question, please try searching for previous discussions, maybe it has already been answered\n - Reposts are fine, but should have at least a couple of weeks in between so that the post can reach a new audience\n - Be nice :)\n\n### Related communities\n\n- [Lemmy.ml libre_culture](https://lemmy.ml/c/libre_culture)\n- [Lemmy.ml privatelife](https://lemmy.ml/c/privatelife)\n- [Lemmy.ml DeGoogle](https://lemmy.ml/c/degoogle)\n- [Lemmy.ca privacy](https://lemmy.ca/c/privacy)\n\nmuch thanks to @gary_host_laptop for the logo design :)","removed":false,"published":"2019-11-15T23:50:53.712299Z","updated":"2024-11-22T21:30:19.947538Z","deleted":false,"nsfw":false,"actor_id":"https://lemmy.ml/c/privacy","local":false,"icon":"https://lemmy.ml/pictrs/image/h1ChnLuBHr.png","banner":"https://lemmy.ml/pictrs/image/DBjcqOW9ds.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":16,"visibility":"Public"},"counts":{"comment_id":13198121,"score":2,"upvotes":2,"downvotes":0,"published":"2024-12-06T06:14:54.908562Z","child_count":1},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13179129,"creator_id":4299,"post_id":15854669,"content":"I just checked my KeePass and turns out I still have the entry in the recycle bin. \nIt was 5 digits. Admittedly, that was \"back in 2012,\" but still. For shame, Bank Austria!","removed":false,"published":"2024-12-05T15:34:07.829245Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15400380","local":false,"path":"0.13171801.13176153.13176496.13179129","distinguished":false,"language_id":37},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15854669,"name":"FBI Warns Americans to Start Using Encrypted Messaging Apps","url":"https://gizmodo.com/fbi-warns-americans-to-start-using-encrypted-messaging-apps-2000533800","creator_id":6700029,"community_id":6212,"removed":false,"locked":false,"published":"2024-12-05T00:00:36.152983Z","deleted":false,"nsfw":false,"embed_title":"FBI Warns Americans to Start Using Encrypted Messaging Apps","embed_description":"It's all about protecting against China, but there's the added benefit of protecting against Trump.","thumbnail_url":"https://sh.itjust.works/pictrs/image/bebd4cfc-588a-469c-9fa3-387ce880dbd0.jpeg","ap_id":"https://sh.itjust.works/post/29033194","local":false,"language_id":37,"featured_community":false,"featured_local":false},"community":{"id":6212,"name":"cybersecurity","title":"Cybersecurity","description":"c/cybersecurity is a community centered on the cybersecurity and information security profession. You can come here to discuss news, post something interesting, or just chat with others.\n\n**THE RULES**\n\n**Instance Rules**\n\n- Be respectful. Everyone should feel welcome here.\n- No bigotry - including racism, sexism, ableism, homophobia, transphobia, or xenophobia.\n- No Ads / Spamming.\n- No pornography.\n\n**Community Rules**\n- Idk, keep it semi-professional?\n- Nothing illegal. We're all ethical here.\n- Rules will be added/redefined as necessary.\n\nIf you ask someone to hack your \"friends\" socials you're just going to get banned so don't do that.\n\n**Learn about hacking**\n\n[Hack the Box](https://www.hackthebox.com/)\n\n[Try Hack Me](https://tryhackme.com/)\n\n[Pico Capture the flag](https://www.picoctf.org/)\n\n**Other security-related communities**\n!databreaches@lemmy.zip\n!netsec@lemmy.world\n!securitynews@infosec.pub\n!cybersecurity@infosec.pub\n!pulse_of_truth@infosec.pub\n\nNotable mention to !cybersecuritymemes@lemmy.world","removed":false,"published":"2023-06-08T20:38:31.984163Z","updated":"2024-12-09T12:18:05.481209Z","deleted":false,"nsfw":false,"actor_id":"https://sh.itjust.works/c/cybersecurity","local":false,"icon":"https://sh.itjust.works/pictrs/image/c38fd5ff-821e-45c9-b2ee-957d0321d2e2.webp","banner":"https://midwest.social/pictrs/image/914ad12e-7717-4d9f-8996-37a6816f38ec.jpeg","hidden":false,"posting_restricted_to_mods":false,"instance_id":32,"visibility":"Public"},"counts":{"comment_id":13179129,"score":5,"upvotes":5,"downvotes":0,"published":"2024-12-05T15:34:07.829245Z","child_count":0},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13177153,"creator_id":4299,"post_id":15828203,"content":"# Python\nEssentially I'm extracting strings from the word search and compare them to the desired value. For part one that means extracting from an X in eight directions. Because I'm reading from the central X outwards, I don't need to reverse any of them. \nPart two reads two strings in an X-shape around the coordinates of each X. The resulting strings are filtered down to include only \"MAS\" and \"SAM\". If there are exactly two strings we found an X-MAS.\n```python\nfrom pathlib import Path\n\n\ndef parse_input(input: str) -> list[str]:\n return input.strip().splitlines()\n\n\ndef extract_strings_one(m: int, n: int, haystack: list[str], l: int = 4) -> list[str]:\n result = []\n # Right\n if m + l <= len(haystack[n]):\n result.append(haystack[n][m : m + l])\n # Up-Right\n if m + l <= len(haystack[n]) and n > l - 2:\n result.append(\"\".join([haystack[n - i][m + i] for i in range(l)]))\n # Up\n if n > l - 2:\n result.append(\"\".join([haystack[n - i][m] for i in range(l)]))\n # Up-Left\n if m > l - 2 and n > l - 2:\n result.append(\"\".join([haystack[n - i][m - i] for i in range(l)]))\n # Left\n if m > l - 2:\n result.append(\"\".join([haystack[n][m - i] for i in range(l)]))\n # Down-Left\n if m > l - 2 and n + l <= len(haystack):\n result.append(\"\".join([haystack[n + i][m - i] for i in range(l)]))\n # Down\n if n + l <= len(haystack):\n result.append(\"\".join([haystack[n + i][m] for i in range(l)]))\n # Down-Right\n if m + l <= len(haystack[n]) and n + l <= len(haystack):\n result.append(\"\".join([haystack[n + i][m + i] for i in range(l)]))\n return result\n\n\ndef extract_strings_two(m: int, n: int, haystack: list[str], d: int = 1) -> list[str]:\n result = []\n if 0 <= m - d and m + d < len(haystack[n]) and 0 <= n - d and n + d < len(haystack):\n result.append(\"\".join([haystack[n + i][m + i] for i in range(-d, d + 1)]))\n result.append(\"\".join([haystack[n - i][m + i] for i in range(-d, d + 1)]))\n return result\n\n\ndef part_one(input: str) -> int:\n lines = parse_input(input)\n xmas_count = 0\n for i, line in enumerate(lines):\n x = line.find(\"X\", 0)\n while x != -1:\n xmas_count += len(\n list(filter(lambda s: s == \"XMAS\", extract_strings_one(x, i, lines)))\n )\n x = line.find(\"X\", x + 1)\n return xmas_count\n\n\ndef part_two(input: str) -> int:\n lines = parse_input(input)\n x_mas_count = 0\n for i, line in enumerate(lines[1:-1], 1):\n a = line.find(\"A\", 0)\n while a != -1:\n if (\n len(\n list(\n filter(\n lambda s: s in (\"MAS\", \"SAM\"),\n extract_strings_two(a, i, lines),\n )\n )\n )\n == 2\n ):\n x_mas_count += 1\n a = line.find(\"A\", a + 1)\n return x_mas_count\n\n\nif __name__ == \"__main__\":\n input = Path(\"input\").read_text(\"utf-8\")\n print(part_one(input))\n print(part_two(input))\n```","removed":false,"published":"2024-12-05T14:07:43.564008Z","updated":"2024-12-05T14:08:22.021113Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15399047","local":false,"path":"0.13177153","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15828203,"name":"🌚 - 2024 DAY 4 SOLUTIONS - 🌚","body":"# Day 4: Ceres Search\n\n## Megathread guidelines\n- Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)\n- You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://topaz.github.io/paste/ if you prefer sending it through a URL\n\n## FAQ\n- What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268\n- Where do I participate?: https://adventofcode.com/\n- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465","creator_id":144641,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-04T05:53:00.822245Z","deleted":false,"nsfw":false,"ap_id":"https://programming.dev/post/22445571","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13177153,"score":1,"upvotes":1,"downvotes":0,"published":"2024-12-05T14:07:43.564008Z","child_count":0},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13176678,"creator_id":4299,"post_id":15861889,"content":"No need for `floor`, you can just use `len(pages) // 2`.","removed":false,"published":"2024-12-05T13:47:54.441519Z","updated":"2024-12-05T13:48:06.233567Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15398779","local":false,"path":"0.13173733.13176678","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15861889,"name":"🖨️ - 2024 DAY 5 SOLUTIONS - 🖨️","body":"# Day 5: Print Queue\n\n## Megathread guidelines\n- Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)\n- You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://topaz.github.io/paste/ if you prefer sending it through a URL\n\n## FAQ\n- What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268\n- Where do I participate?: https://adventofcode.com/\n- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465","creator_id":144641,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-05T06:37:46.973686Z","deleted":false,"nsfw":false,"ap_id":"https://programming.dev/post/22486116","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13176678,"score":2,"upvotes":2,"downvotes":0,"published":"2024-12-05T13:47:54.441519Z","child_count":1},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13176613,"creator_id":4299,"post_id":15861889,"content":"# Python\nAlso took advantage of `cmp_to_key`.\n```python\nfrom functools import cmp_to_key\nfrom pathlib import Path\n\n\ndef parse_input(input: str) -> tuple[dict[int, list[int]], list[list[int]]]:\n rules, updates = tuple(input.strip().split(\"\\n\\n\")[:2])\n order = {}\n for entry in rules.splitlines():\n values = entry.split(\"|\")\n order.setdefault(int(values[0]), []).append(int(values[1]))\n updates = [[int(v) for v in u.split(\",\")] for u in updates.splitlines()]\n return (order, updates)\n\n\ndef is_ordered(update: list[int], order: dict[int, list[int]]) -> bool:\n return update == sorted(\n update, key=cmp_to_key(lambda a, b: 1 if a in order.setdefault(b, []) else -1)\n )\n\n\ndef part_one(input: str) -> int:\n order, updates = parse_input(input)\n return sum([u[len(u) // 2] for u in (u for u in updates if is_ordered(u, order))])\n\n\ndef part_two(input: str) -> int:\n order, updates = parse_input(input)\n return sum(\n [\n sorted(u, key=cmp_to_key(lambda a, b: 1 if a in order[b] else -1))[\n len(u) // 2\n ]\n for u in (u for u in updates if not is_ordered(u, order))\n ]\n )\n\n\nif __name__ == \"__main__\":\n input = Path(\"input\").read_text(\"utf-8\")\n print(part_one(input))\n print(part_two(input))\n```","removed":false,"published":"2024-12-05T13:44:13.609686Z","updated":"2024-12-05T13:44:58.602249Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15398729","local":false,"path":"0.13176613","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15861889,"name":"🖨️ - 2024 DAY 5 SOLUTIONS - 🖨️","body":"# Day 5: Print Queue\n\n## Megathread guidelines\n- Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)\n- You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://topaz.github.io/paste/ if you prefer sending it through a URL\n\n## FAQ\n- What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268\n- Where do I participate?: https://adventofcode.com/\n- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465","creator_id":144641,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-05T06:37:46.973686Z","deleted":false,"nsfw":false,"ap_id":"https://programming.dev/post/22486116","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13176613,"score":2,"upvotes":2,"downvotes":0,"published":"2024-12-05T13:44:13.609686Z","child_count":0},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13176402,"creator_id":4299,"post_id":15800582,"content":"# Python\nAfter a bunch of fiddling yesterday and today I finally managed to arrive at a regex-only solution for part 2. That `re.DOTALL` is crucial here.\n```python\nimport re\nfrom pathlib import Path\n\n\ndef parse_input_one(input: str) -> list[tuple[int]]:\n p = re.compile(r\"mul\\((\\d{1,3}),(\\d{1,3})\\)\")\n return [(int(m[0]), int(m[1])) for m in p.findall(input)]\n\n\ndef parse_input_two(input: str) -> list[tuple[int]]:\n p = re.compile(r\"don't\\(\\).*?do\\(\\)|mul\\((\\d{1,3}),(\\d{1,3})\\)\", re.DOTALL)\n return [(int(m[0]), int(m[1])) for m in p.findall(input) if m[0] and m[1]]\n\n\ndef part_one(input: str) -> int:\n pairs = parse_input_one(input)\n return sum(map(lambda v: v[0] * v[1], pairs))\n\n\ndef part_two(input: str) -> int:\n pairs = parse_input_two(input)\n return sum(map(lambda v: v[0] * v[1], pairs))\n\n\nif __name__ == \"__main__\":\n input = Path(\"input\").read_text(\"utf-8\")\n print(part_one(input))\n print(part_two(input))\n```","removed":false,"published":"2024-12-05T13:29:15.963Z","updated":"2024-12-05T13:30:02.689783Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15398519","local":false,"path":"0.13176402","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15800582,"name":"🍷 - 2024 DAY 3 SOLUTIONS -🍷","body":"# Day 3: Mull It Over\n\n## Megathread guidelines\n- Keep top level comments as only solutions, if you want to say something other than a solution put it in a new post. (replies to comments can be whatever)\n- You can send code in code blocks by using three backticks, the code, and then three backticks or use something such as https://topaz.github.io/paste/ if you prefer sending it through a URL\n\n## FAQ\n- What is this?: Here is a post with a large amount of details: https://programming.dev/post/6637268\n- Where do I participate?: https://adventofcode.com/\n- Is there a leaderboard for the community?: We have a programming.dev leaderboard with the info on how to join in this post: https://programming.dev/post/6631465","creator_id":144641,"community_id":104675,"removed":false,"locked":false,"published":"2024-12-03T08:48:44.783137Z","updated":"2024-12-03T08:51:03.407081Z","deleted":false,"nsfw":false,"ap_id":"https://programming.dev/post/22414202","local":false,"language_id":0,"featured_community":false,"featured_local":false},"community":{"id":104675,"name":"advent_of_code","title":"Advent Of Code","description":"An unofficial home for the advent of code community on programming.dev!\n\nAdvent of Code is an annual Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.\n\n## [AoC 2024](https://adventofcode.com/2024)\nSolution Threads\n| M | T | W | T | F | S | S |\n|----|----|----|----|----|----|----|\n| | | | | | | [1](https://programming.dev/post/22325778) | \n| [2](https://programming.dev/post/22371687) | [3](https://programming.dev/post/22414202)| [4](https://programming.dev/post/22445571)| [5](https://programming.dev/post/22486116)| [6](https://programming.dev/post/22521066)| [7](https://programming.dev/post/22558447)| [8](https://programming.dev/post/22596237) |\n| [9](https://programming.dev/post/22635267) | [10](https://programming.dev/post/22672699)| [11](https://programming.dev/post/22710192) | [12](https://programming.dev/post/22749375)| [13](https://programming.dev/post/22790338)|[14](https://programming.dev/post/22827716)| [15](https://programming.dev/post/22859948)|\n|[16](https://programming.dev/post/22897969)|[17](https://programming.dev/post/22935266)|[18](https://programming.dev/post/22972406)|[19](https://programming.dev/post/23017702)|[20](https://programming.dev/post/23064988)|[21](https://programming.dev/post/23107860)|[22](https://programming.dev/post/23151169)|\n|[23](https://programming.dev/post/23198319)|[24](https://programming.dev/post/23243817)|[25](https://programming.dev/post/23287241)|||||\n\n#### __Rules/Guidelines__\n- Follow the programming.dev instance rules\n- Keep all content related to advent of code in some way\n- If what youre posting relates to a day, put in brackets the year and then day number in front of the post title (e.g. [2024 Day 10])\n- When an event is running, keep solutions in the solution megathread to avoid the community getting spammed with posts\n\n#### __Relevant Communities__\n- [!programming@programming.dev](https://programming.dev/c/programming) \n- [!challenges@programming.dev](https://programming.dev/c/challenges) \n\n#### __Relevant Links__\n- [Advent of Code Homepage](https://adventofcode.com/)\n\n#### __Credits__\n\nIcon base by [Lorc](https://lorcblog.blogspot.com/) under [CC BY 3.0](https://creativecommons.org/licenses/by/3.0/) with modifications to add a gradient\n\n\n```\nconsole.log('Hello World')\n```","removed":false,"published":"2023-08-01T03:37:37.261616Z","updated":"2024-12-25T05:25:17.976437Z","deleted":false,"nsfw":false,"actor_id":"https://programming.dev/c/advent_of_code","local":false,"icon":"https://programming.dev/pictrs/image/9fcac0c0-32b5-40c9-bb7c-53bc37d32884.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":22,"visibility":"Public"},"counts":{"comment_id":13176402,"score":2,"upvotes":2,"downvotes":0,"published":"2024-12-05T13:29:15.963Z","child_count":0},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13176153,"creator_id":4299,"post_id":15854669,"content":"Right? Had a bank account once, where the login password could only have up to 8 characters. And only digits.","removed":false,"published":"2024-12-05T13:02:10.767318Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15398136","local":false,"path":"0.13171801.13176153","distinguished":false,"language_id":37},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15854669,"name":"FBI Warns Americans to Start Using Encrypted Messaging Apps","url":"https://gizmodo.com/fbi-warns-americans-to-start-using-encrypted-messaging-apps-2000533800","creator_id":6700029,"community_id":6212,"removed":false,"locked":false,"published":"2024-12-05T00:00:36.152983Z","deleted":false,"nsfw":false,"embed_title":"FBI Warns Americans to Start Using Encrypted Messaging Apps","embed_description":"It's all about protecting against China, but there's the added benefit of protecting against Trump.","thumbnail_url":"https://sh.itjust.works/pictrs/image/bebd4cfc-588a-469c-9fa3-387ce880dbd0.jpeg","ap_id":"https://sh.itjust.works/post/29033194","local":false,"language_id":37,"featured_community":false,"featured_local":false},"community":{"id":6212,"name":"cybersecurity","title":"Cybersecurity","description":"c/cybersecurity is a community centered on the cybersecurity and information security profession. You can come here to discuss news, post something interesting, or just chat with others.\n\n**THE RULES**\n\n**Instance Rules**\n\n- Be respectful. Everyone should feel welcome here.\n- No bigotry - including racism, sexism, ableism, homophobia, transphobia, or xenophobia.\n- No Ads / Spamming.\n- No pornography.\n\n**Community Rules**\n- Idk, keep it semi-professional?\n- Nothing illegal. We're all ethical here.\n- Rules will be added/redefined as necessary.\n\nIf you ask someone to hack your \"friends\" socials you're just going to get banned so don't do that.\n\n**Learn about hacking**\n\n[Hack the Box](https://www.hackthebox.com/)\n\n[Try Hack Me](https://tryhackme.com/)\n\n[Pico Capture the flag](https://www.picoctf.org/)\n\n**Other security-related communities**\n!databreaches@lemmy.zip\n!netsec@lemmy.world\n!securitynews@infosec.pub\n!cybersecurity@infosec.pub\n!pulse_of_truth@infosec.pub\n\nNotable mention to !cybersecuritymemes@lemmy.world","removed":false,"published":"2023-06-08T20:38:31.984163Z","updated":"2024-12-09T12:18:05.481209Z","deleted":false,"nsfw":false,"actor_id":"https://sh.itjust.works/c/cybersecurity","local":false,"icon":"https://sh.itjust.works/pictrs/image/c38fd5ff-821e-45c9-b2ee-957d0321d2e2.webp","banner":"https://midwest.social/pictrs/image/914ad12e-7717-4d9f-8996-37a6816f38ec.jpeg","hidden":false,"posting_restricted_to_mods":false,"instance_id":32,"visibility":"Public"},"counts":{"comment_id":13176153,"score":8,"upvotes":8,"downvotes":0,"published":"2024-12-05T13:02:10.767318Z","child_count":3},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":13161492,"creator_id":4299,"post_id":15811254,"content":"What do you mean? I usually find Wikipedia's explanations quite helpful. Maybe a little heady at times, but always factual.","removed":false,"published":"2024-12-04T18:24:31.722128Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15384904","local":false,"path":"0.13148386.13149800.13149961.13161492","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15811254,"name":"Christian Nationalists And Bigots Stump For Ken Paxton In SCOTUS Age Verification Case","url":"https://www.techdirt.com/2024/12/02/christian-nationalists-and-bigots-stump-for-ken-paxton-in-scotus-age-verification-case/","body":"*from the the-real-agenda dept*","creator_id":12976624,"community_id":252,"removed":false,"locked":false,"published":"2024-12-03T17:03:20.815988Z","deleted":false,"nsfw":false,"embed_title":"Christian Nationalists And Bigots Stump For Ken Paxton In SCOTUS Age Verification Case","embed_description":"Scores of organizations from across the anti-pornography movement have filed amicus briefs supporting the state of Texas and Attorney General Ken Paxton in a U.S. Supreme Court case dealing with hi…","thumbnail_url":"https://www.techdirt.com/wp-content/uploads/2022/02/legal-issues.jpg","ap_id":"https://lemmy.blahaj.zone/post/19234960","local":false,"language_id":37,"featured_community":false,"featured_local":false},"community":{"id":252,"name":"privacy","title":"Privacy","description":"# A place to discuss privacy and freedom in the digital world.\n\nPrivacy has become a very important issue in modern society, with companies and governments constantly abusing their power, more and more people are waking up to the importance of digital privacy. \n\nIn this community everyone is welcome to post links and discuss topics related to privacy.\n\n### Some Rules\n\n - Posting a link to a website containing tracking isn't great, if contents of the website are behind a paywall maybe copy them into the post\n - Don't promote proprietary software\n - Try to keep things on topic\n - If you have a question, please try searching for previous discussions, maybe it has already been answered\n - Reposts are fine, but should have at least a couple of weeks in between so that the post can reach a new audience\n - Be nice :)\n\n### Related communities\n\n- [Lemmy.ml libre_culture](https://lemmy.ml/c/libre_culture)\n- [Lemmy.ml privatelife](https://lemmy.ml/c/privatelife)\n- [Lemmy.ml DeGoogle](https://lemmy.ml/c/degoogle)\n- [Lemmy.ca privacy](https://lemmy.ca/c/privacy)\n\nmuch thanks to @gary_host_laptop for the logo design :)","removed":false,"published":"2019-11-15T23:50:53.712299Z","updated":"2024-11-22T21:30:19.947538Z","deleted":false,"nsfw":false,"actor_id":"https://lemmy.ml/c/privacy","local":false,"icon":"https://lemmy.ml/pictrs/image/h1ChnLuBHr.png","banner":"https://lemmy.ml/pictrs/image/DBjcqOW9ds.png","hidden":false,"posting_restricted_to_mods":false,"instance_id":16,"visibility":"Public"},"counts":{"comment_id":13161492,"score":3,"upvotes":3,"downvotes":0,"published":"2024-12-04T18:24:31.722128Z","child_count":0},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false},{"comment":{"id":12988429,"creator_id":4299,"post_id":15566602,"content":"The first 'E'.","removed":false,"published":"2024-11-26T06:52:09.059988Z","deleted":false,"ap_id":"https://sh.itjust.works/comment/15244598","local":false,"path":"0.12988317.12988429","distinguished":false,"language_id":0},"creator":{"id":4299,"name":"Chais","avatar":"https://sh.itjust.works/pictrs/image/2e9ff40f-9ba2-41a1-b27b-494d66b4a3c6.png","banned":false,"published":"2023-06-12T20:58:28.747822Z","actor_id":"https://sh.itjust.works/u/Chais","local":false,"deleted":false,"bot_account":false,"instance_id":32},"post":{"id":15566602,"name":"The most open to exploits perhaps","url":"https://lemmy.ml/pictrs/image/bb961e83-f823-4f2f-ab88-ed30ed29fad5.jpeg","creator_id":580,"community_id":24,"removed":false,"locked":false,"published":"2024-11-26T01:11:18.812741Z","deleted":false,"nsfw":false,"thumbnail_url":"https://lemmy.ml/pictrs/image/bb961e83-f823-4f2f-ab88-ed30ed29fad5.jpeg","ap_id":"https://lemmy.ml/post/22907761","local":false,"language_id":37,"featured_community":false,"featured_local":false},"community":{"id":24,"name":"programmerhumor","title":"Programmer Humor","description":"Post funny things about programming here! (Or just rant about your favourite programming language.)\n\n# Rules:\n\n* Posts must be relevant to programming, programmers, or computer science.\n* No NSFW content.\n* Jokes must be in good taste. No hate speech, bigotry, etc.","removed":false,"published":"2019-08-19T09:46:48.488224Z","updated":"2022-03-08T19:55:12.303424Z","deleted":false,"nsfw":false,"actor_id":"https://lemmy.ml/c/programmerhumor","local":false,"icon":"https://lemmy.ml/pictrs/image/c0ed0a36-2496-4b4d-ac77-7d2fd7f2b5b7.png","banner":"https://lemmy.ml/pictrs/image/dd918f22-84fa-48d5-975a-c94981058c18.jpeg","hidden":false,"posting_restricted_to_mods":false,"instance_id":16,"visibility":"Public"},"counts":{"comment_id":12988429,"score":4,"upvotes":4,"downvotes":0,"published":"2024-11-26T06:52:09.059988Z","child_count":0},"creator_banned_from_community":false,"banned_from_community":false,"creator_is_moderator":false,"creator_is_admin":false,"subscribed":"NotSubscribed","saved":false,"creator_blocked":false}],"posts":[],"moderates":[]}

Chais @ Chais @sh.itjust.works Posts 30Comments 688Joined 2 yr. ago

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Chais @ Chais @sh.itjust.works

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688
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2 yr. ago