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RippleNav – A web instrument provides real-time visual feedback on thought focus

https://access.ripplenav.org/
1•RRwood•1m ago•0 comments

Saudi's Ceer unveils first EVs

https://www.reuters.com/world/middle-east/saudis-ceer-unveils-first-evs-bid-build-regional-auto-p...
1•Propelloni•2m ago•0 comments

Welcome Silona Bonewald, New MetaBrainz Foundation Executive Director

https://blog.metabrainz.org/2026/09/22/welcome-silona-bonewald-new-metabrainz-foundation-executiv...
1•aerozol•3m ago•1 comments

Show HN: Easytris – Tetris that wants you to win

https://medv.io/easytris/
1•medv•5m ago•0 comments

A Tribute to Donald Knuth (2024)

https://paramrathour.github.io/blog/knuth/
1•signa11•6m ago•0 comments

Create AI Image Free – No Sign-Up Needed

https://www.createaiimage.net/
1•wsm123456•6m ago•0 comments

Scanner says the HTML attachment is clean. What happens when you open it?

https://mohitkhare.com/blog/file-attack-html-smuggling/
1•mkfeuhrer•9m ago•0 comments

Chewbacca's Ancestor Is Real

https://maxhawtdawg.com/
1•zacksiri•9m ago•0 comments

The Set of Math-Sterpieces

https://paramrathour.github.io/blog/math-book-recommendations/
1•signa11•12m ago•0 comments

Reverse-Engineering Jane Street's ASIC

https://mooofin.github.io/portfolio/blog/jane-street-asic.html
1•allenleee•12m ago•0 comments

How people are testing AI agents?

1•sanathbhat•13m ago•0 comments

Frontier Overhangs

https://stratechery.com/2026/frontier-overhangs/
1•tosh•16m ago•0 comments

Some Old Expectations for the New Apple

https://taoofmac.com/space/blog/2026/09/22/0709
2•rcarmo•18m ago•0 comments

Physics Problem Finder

https://beneke7.github.io/physics-problems-corpus/
1•bbene•19m ago•0 comments

The Armored Sarcophagus Saving Ukrainian Soldiers

https://www.theatlantic.com/international/2026/09/ukraine-frontline-medical-evacuations/688638/
1•mkesper•22m ago•0 comments

OpenCode Reloaded

https://anoma.ly/notes/opencode-reloaded/
1•pretext•26m ago•0 comments

Proposed Group: Browser Data Portability Community Group

https://www.w3.org/community/blog/2026/09/11/proposed-group-browser-data-portability-community-gr...
2•enos_feedler•31m ago•1 comments

Raspberry Pi locks down RAM upgrades in Firmware [video]

https://www.youtube.com/watch?v=ltofM26akZQ
1•juliethefoxcoon•34m ago•0 comments

Orphaned VMs: Running VMs Uninterrupted While Host Kernel Is Offline

https://www.phoronix.com/news/Orphaned-VMs-Linux-Patches
1•daandewit•35m ago•0 comments

0x025 – System One Models (Jev)

https://unzip.dev/0x025-system-one-models/
1•vismit2000•35m ago•0 comments

Xenobiome Command – a colony SIM that runs offline in the browser

https://play.xenobiome.net/?src=hn
1•jonnyka•39m ago•0 comments

Skill and UI kit to understand PRs faster

https://github.com/annanay25/explain-pr
2•annanay•44m ago•1 comments

She died at the San Diego border. A surveillance camera was in plain sight

https://www.technologyreview.com/2026/09/21/1144170/border-towers-surveillance-feature/
1•joozio•47m ago•0 comments

Move On – export your AI chats, file GDPR deletion, escalate if ignored

https://github.com/ur-grue/move-on
1•ur-grue•47m ago•0 comments

Show HN: I made ShipStreak to keep daily shipping gaps public

https://www.shipstreak.space/?via=hn
1•kljr_dev•48m ago•0 comments

Pakistan Orders Hospital Beds Clear for Mass Casualty Ahead of Protest

https://www.dropsitenews.com/p/pakistan-military-protest-imran-khan-sisters-detained-hospitals-beds
1•xbmcuser•51m ago•0 comments

Ask HN: Is Astra's writing starting to bother anyone else?

2•demibabs•51m ago•2 comments

QBZ (Qobuz desktop client for Linux) shutting down

https://qbz.lol/
2•herrherrmann•52m ago•0 comments

Show HN: Cheap and easy throwaway VPN server

https://a.l3x.in/blog/throwaway-vpn/
1•alexfortin•57m ago•1 comments

AI staff complain of mental toll over fears of threat to society

https://www.ft.com/content/60870960-f433-48ca-bc2c-708686a69ae7
2•bazzmt•58m ago•0 comments
Open in hackernews

Generating Mazes with Inductive Graphs (2017)

https://jelv.is/blog/Generating-Mazes-with-Inductive-Graphs/
20•todsacerdoti•1y ago

Comments

tomfly•1y ago
where is the entrance and exit?
Jaxan•1y ago
Doesn’t matter, because all positions are reachable. So just pick any two positions at the border and remove a wall.
kazinator•1y 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•1y 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•1y 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•1y 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.