frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

fp.

Open in hackernews

Generating Mazes with Inductive Graphs (2017)

https://jelv.is/blog/Generating-Mazes-with-Inductive-Graphs/
20•todsacerdoti•10mo ago

Comments

tomfly•10mo ago
where is the entrance and exit?
Jaxan•10mo ago
Doesn’t matter, because all positions are reachable. So just pick any two positions at the border and remove a wall.
kazinator•10mo ago
Here is a maze that was generated recursively starting at the upper left cell.

  +    +----+----+----+----+----+----+----+----+----+
  |    |                        |                   |
  |    |                        |                   |
  +    +----+----+    +----+    +----+    +----+    +
  |              |         |                   |    |
  |              |         |                   |    |
  +----+----+    +    +----+----+----+----+----+    +
  |              |    |                        |    |
  |              |    |                        |    |
  +    +----+----+    +    +----+----+----+    +    +
  |         |              |              |    |    |
  |         |              |              |    |    |
  +    +----+    +    +----+----+----+    +    +----+
  |              |    |                   |    |    |
  |              |    |                   |    |    |
  +----+----+----+    +    +----+----+----+    +    +
  |                        |                   |    |
  |                        |                   |    |
  +    +----+----+----+    +    +----+----+----+    +
  |    |    |              |    |              |    |
  |    |    |              |    |              |    |
  +    +    +    +    +----+    +    +----+    +    +
  |    |    |    |    |         |    |         |    |
  |    |    |    |    |         |    |         |    |
  +    +    +    +    +----+----+----+    +    +    +
  |    |    |    |    |                   |         |
  |    |    |    |    |                   |         |
  +    +    +----+    +    +----+----+    +----+----+
  |              |         |                        |
  |              |         |                        |
  +----+----+----+----+----+----+----+----+----+    +

It matters to start there because it will be easier if you go backwards.

The maze has 100 cells. For each cell, we can calculate which exit goes back toward the entrance, assigning the letters U, D, L, R:

  U R R D L L R D L L
  U L L D L U L L L U
  R R U D D L L L L U
  U L D L L R R D U U
  U L L U D L L L U D
  R R R U L R R R U D
  U D R R U U R R D D
  U D U U R U U D L D
  U D U U D L L L U L
  U L L U L R R U L L
Stats:

  L - 33
  U - 29
  R - 20
  D - 18
Left and Up are more frequent back-to-entrance escapes than Right or Down. This is because of the way the maze was generated.

To check the hypothesis, we should analyze it in the other direction. For each cell, determine the exit which heads in the direction of the exit:

  D R R D L L R D L L
  D R D D L U L L L U
  D L L D D L L L L U
  D L R D L R R D D U
  R R U D D L L L U D
  R R R R D R R R U D
  U D R D L U R R D D
  U D U D R U U D L D
  U D U D R R R D U L
  U L L R U R R R R D
Stats:

  D - 30
  R - 28
  L - 24
  U - 18
There is a weaker bias for the D-R axis toward the exit, compared to the L-U axis toward the entrance. I suspect if we study larger numbers of larger mazes, we will find similar findings.

So that is to say, it is easier to navigate the maze in the reverse direction: the heuristic to try left/up exits will work more often than the right/down in the proper direction.

smartmic•10mo ago
From the book "Mazes for Programmers" by Jamis Buck, 2015, The Pragmatic Programmers (a must-read for any maze/programming enthusiast!):

> Aren't mazes supposed to have starting points and end points? […] honestly, […] it's entirely up to you. […] The maze […] is a perfect maze, and one of the attributes of a perfect maze is that there exists exactly one path between any two cells in it. […] You pick them, and there's guaranteed to be a path between them.

You do not need to choose an entrance or exit only on the sides, but you can also choose "Pacman-style" where the goal is to reach points inside the maze.

"Perfect" refers to the mathematical/logical properties of a maze (i.e. no loops), not the aesthetical aspect. I have not checked though if the mazes in the source here are all perfect.

kazinator•10mo ago
While you can put the entrance and exit wherever you want, if you know that the maze was generated by a recursive branching process which had a starting point somewhere, it probably behooves you to put the start at that point corresponding to the root of the tree, so that the maze wanderer faces the most branching choices.

Laying out the abstract maze tree into the rectilinear grid of cells obfuscates the tree somewhat, but not entirely. A process that generates from upper left to lower right, for instance, will tend to generate cells whose parent-headed exits going left and up more often than not, making the reverse direction a bit easier.

(Again, it depends on the maze generation process.)

kazinator•10mo ago
Making random mazes in a rectilinear grid is a good exercise for one big reason: mazes are not all the same. Mazes have style can be very knotty and twisty, or have long passages. You can add hacks into a given algorithm to vary the style, but there are certain things it won't necessarily do.

Zuckerberg's internal emails rendered as Facebook Messenger

https://zuckmail.vercel.app/
1•not-chatgpt•1m ago•0 comments

Daily LNG freight rates jump over 40% amid Mideast strikes

https://www.reuters.com/business/energy/daily-lng-freight-rates-jump-over-40-amid-mideast-strikes...
1•geox•1m ago•0 comments

Solar Time vs. Standard Time heat map chart

https://blog.poormansmath.net/images/SolarTimeVsStandardTime.png
1•ivewonyoung•2m ago•0 comments

Show HN: One-click ComfyUI setup for RTX 50-series on Windows (cu130, no Docker)

https://github.com/hiroki-abe-58/ComfyUI-Win-Blackwell
1•GeneLab_999•3m ago•0 comments

Ask HN: Codex CLI error reveals "GPT-5.4-ab-arm2" string

1•quantisan•5m ago•0 comments

The Optimization Trap: Why the Birth Rate Can't Be Fixed

https://tantaman.com/2026-03-02-fertility-is-not-economics.html
1•tantaman•5m ago•0 comments

OpenAI, Pentagon add more surveillance protections to AI deal

https://www.axios.com/2026/03/03/openai-pentagon-ai-surveillance
1•foobarqux•6m ago•1 comments

Meteorologist warns federal cuts are undermining weather forecasts nationwide

https://www.lehighvalleynews.com/environment-science/local-meteorologist-warns-federal-cuts-are-u...
1•mkmk•8m ago•0 comments

Decimal Time (French Republican Clock)

https://en.wikipedia.org/wiki/Decimal_time
1•rawgabbit•12m ago•0 comments

Made a register-based bytecode VM in C, heres how the handler table works

https://github.com/goofgef/ZagMate
1•goofgef•19m ago•1 comments

The exploitation paradox in open source

https://lwn.net/SubscriberLink/1058031/a1b77f8039faed6c/
1•pabs3•22m ago•0 comments

Coasty automates anything – this post was written by the CUA itself

1•PrateekJ17•23m ago•1 comments

"Here is a re-post of an internal note"

https://twitter.com/sama/status/2028640354912923739
1•davidbarker•23m ago•1 comments

Ars Technica Fires Reporter After AI Controversy Involving Fabricated Quotes

https://futurism.com/artificial-intelligence/ars-technica-fires-reporter-ai-quotes
1•danso•27m ago•0 comments

Show HN: PHP 8 disable_functions bypass PoC

https://github.com/m0x41nos/TimeAfterFree
5•m0x41nos•27m ago•0 comments

Anthropic Adds Free Memory Feature and Import Tool to Lure ChatGPT Users

https://www.macrumors.com/2026/03/02/anthropic-memory-import-tool/
1•mgh2•27m ago•0 comments

LibreOffice hits back at critics, says its UI is better than Microsoft Office's

https://www.neowin.net/news/libreoffice-hits-back-at-its-critics-says-its-ui-is-better-than-micro...
6•bundie•32m ago•2 comments

Dyndispatch – Dynamic Dispatch for Python

https://git.sr.ht/~shakna/dyndispatch
2•shakna•32m ago•0 comments

China-based assets being removed from the Asset Store on March 31st

https://discussions.unity.com/t/a-notice-for-asset-store-assets-from-publishers-in-greater-china/...
3•linolevan•34m ago•1 comments

Odido Security Breach – 6M Customers (Full Timeline and Analysis)

https://danicfilip.com/blog/odido-hack-2026-full-timeline-and-analysis/
1•softwarelounge•34m ago•0 comments

Show HN: VCBacked – Find venture funded startups for your business, fund, agency

https://www.vcbacked.co
1•veritas9•35m ago•0 comments

Show HN: Evan-proxy, better teenager phone management

https://github.com/chrissnell/evan-proxy
1•chrissnell•38m ago•0 comments

Revealed Preferences

https://writing.nikunjk.com/p/revealed-preferences
1•sshh12•39m ago•0 comments

Kalshi: Prediction Markets Need 'Moral Side' After Halting Khamenei Trades

https://www.barrons.com/articles/kalshi-prediction-market-iran-ayatollah-khamenei-fced1463
3•petethomas•44m ago•0 comments

Show HN: ApplyPilot – AI Agent that applies to jobs for you

https://github.com/Pickle-Pixel/ApplyPilot
1•pickle-pixel•45m ago•0 comments

Working with the Kernel Development Community

https://kernel.org/doc/html/latest/process/index.html
2•themaxdavitt•47m ago•0 comments

Offline 23 Hours a Day

https://sive.rs/off23
7•tinkelenberg•55m ago•1 comments

Google just killed my project

5•othmanosx•58m ago•2 comments

AI Web Search and Scraping

https://github.com/larryste1/web-search-tool
1•larryste•1h ago•1 comments

Geo-Strategy #8: The Iran Trap

https://www.youtube.com/watch?v=7y_hbz6loEo
5•bentcorner•1h ago•1 comments