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•8mo ago

Comments

tomfly•8mo ago
where is the entrance and exit?
Jaxan•8mo ago
Doesn’t matter, because all positions are reachable. So just pick any two positions at the border and remove a wall.
kazinator•8mo 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•8mo 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•8mo 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•8mo 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.

Out-of-Context: Constrained Tool Based Exploration of Context

https://www.gojiberries.io/out-of-context-constrained-tool-based-exploration-of-context/
1•neehao•35s ago•0 comments

Iran's Revolutionary Guards declare 'red line' on security as protests escalate

https://www.france24.com/en/middle-east/20260110-iran-s-revolutionary-guards-declare-red-line-on-...
2•mooreds•7m ago•0 comments

MVP = Embarrassing

https://www.mooreds.com/wordpress/archives/3725
1•mooreds•7m ago•0 comments

Show HN: WebRTC-rs/rtc – A Sans-I/O WebRTC Stack for Rust

1•rainliu•7m ago•0 comments

Retrotransposon drives cancer by altering 3D genome structure

https://www.stjude.org/media-resources/news-releases/2026-medicine-science-news/retrotransposon-d...
1•birriel•8m ago•0 comments

Beginner Race – Marble Madness (FM Towns) Music

https://www.youtube.com/watch?v=nDjRZ674c_4
1•doener•8m ago•0 comments

Monterey County bans short-term rentals in unincorporated areas

https://www.sfgate.com/bayarea/article/calif-county-votes-short-term-rental-ban-21285928.php
2•abustamam•9m ago•0 comments

Show HN: MCP Server for Job Search

https://github.com/jobswithgpt/mcp
3•sp1982•9m ago•0 comments

Kubernetes Was Overkill. We Moved to Docker Compose and Saved 60 Hours

https://medium.com/engineering-playbook/kubernetes-was-overkill-we-moved-to-docker-compose-and-sa...
2•firesteelrain•13m ago•0 comments

SpaceX gets FCC approval to launch 7,500 more Starlink satellites

https://techcrunch.com/2026/01/10/spacex-gets-fcc-approval-to-launch-7500-more-starlink-satellites/
1•geox•14m ago•0 comments

Annote: Writing Java using only annotations

https://github.com/kusoroadeolu/annote
1•tempodox•15m ago•0 comments

Show HN: Horizon Engine – C++20 3D FPS Game Engine with ECS and Modern Renderer

https://github.com/jackthepunished/horizon-engine
1•bhdr26k•15m ago•1 comments

Optimism with Footnotes

https://www.gatesnotes.com/the-year-ahead-2026
1•mooreds•17m ago•0 comments

Bryan Johnson Sought Control via Confidentiality Agreements

https://www.nytimes.com/2025/03/21/technology/bryan-johnson-blueprint-confidentiality-agreements....
2•simonebrunozzi•18m ago•0 comments

Answer Set Programming (PDF, 2019)

https://www.cs.utexas.edu/~vl/teaching/378/ASP.pdf
2•tempodox•18m ago•0 comments

Python NumPy Tutorial with Jupyter and Colab (CS231n)

https://cs231n.github.io/python-numpy-tutorial/
2•astdb•19m ago•0 comments

Just updated CommitGuard's landing page, does it explain the product?

https://commitguard.ai
1•moshetanzer•22m ago•1 comments

US used powerful mystery weapon that brought Venezuelan soldiers to their knees

https://nypost.com/2026/01/10/world-news/us-used-powerful-sonic-weapon-in-venezuela-during-raid-t...
2•petermcneeley•26m ago•0 comments

Tux Paint

https://tuxpaint.org/
3•1317•26m ago•1 comments

Show HN: Human or AI-made song detector and 100% Private Audio Mastering

https://kliga.com
1•aswinsilvadasan•29m ago•0 comments

Show HN: EB3F A framework to turn LLM audits into a legal-grade

1•seesea•29m ago•0 comments

Big Tech spared strict rules in EU digital regulations overhaul, sources say

https://www.reuters.com/business/media-telecom/big-tech-spared-strict-rules-eu-digital-rule-overh...
3•TechTechTech•35m ago•0 comments

The Nature of Security Failure

1•__spirit__•38m ago•0 comments

I Cannot SSH into My Server Anymore (and That's Fine)

https://soap.coffee/~lthms/posts/i-cannot-ssh-into-my-server-anymore.html
1•birdculture•39m ago•0 comments

Humanity Wins

https://www.lesswrong.com/posts/dw3NZot9kKcY5dacL/how-humanity-wins
2•PhilosophyForAI•42m ago•0 comments

Unstructured Document Ingestion Pipeline

1•moaffaneh•44m ago•0 comments

Show HN: Sebastos: a sync client for Standard Ebooks

https://github.com/grahame/sebastos
2•grahameb•45m ago•0 comments

Show HN: buse – automate your browser from the terminal

https://github.com/rinvii/buse
2•rinvi•45m ago•0 comments

Tests for Autism? Companies Are Selling Them, but Research Is Still Scant

https://www.nytimes.com/2026/01/07/health/autism-tests-skin-hair-antibodies.html
1•bookofjoe•51m ago•1 comments

People Not People

https://robinrendle.com/notes/people-not-people/
1•treadump•55m ago•0 comments