frontpage.
newsnewestaskshowjobs

Open Source @Github

fp.

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.

Strangers pretrained a language model with HF PRs and a cron job

1•somevyn•7m ago•0 comments

'Naked Dressing' Is Spreading and It's Making Things Awkward

https://www.wsj.com/style/fashion/naked-dressing-hailey-bieber-madonna-d2a1d94b
1•petethomas•15m ago•0 comments

Moochacha

https://codeberg.org/markdascher/moochacha
2•sillysaurusx•15m ago•0 comments

J3blocks

https://codeberg.org/amano.kenji/j3blocks
1•sillysaurusx•16m ago•0 comments

Show HN: Nuking the crap Claude left in the codebase – CCN

https://github.com/jonhardwick-spec/ccn
1•jonhardwickspec•18m ago•0 comments

Running Kimi K3 on MI355X at Better Performance per Dollar Than B300

https://www.wafer.ai/blog/kimi-k3-mi355x
4•ilreb•28m ago•0 comments

Booting Fuchsia's Zircon on a Homebrew RISC-V SoC, on an Artix-7 FPGA

https://www.hdlfactory.com/post/2026/07/19/cocoapuffs-booting-fuchsias-zircon-kernel-on-a-risc-v-...
3•mbStavola•30m ago•0 comments

Sick of waiting for agents to run and then having to debug

1•seafaithless•31m ago•1 comments

Ask HN: Collection of Best Pitch Decks?

3•carbonclaw•32m ago•0 comments

PostgreSQL and the Linux OOM Killer: A Better Default

https://clickhouse.com/blog/strict-memory-overcommit-for-postgres
1•saisrirampur•37m ago•0 comments

Don't credit the LLM

https://isaacsu.com/2026/08/dont-credit-the-llm/
5•isaacsu•42m ago•2 comments

Safeguards Based on Copyable Context Cannot Provide Reliable Safety for LLMs

https://arxiv.org/abs/2607.27951
1•sbulaev•42m ago•0 comments

Karpathy's Pelican

https://twitter.com/karpathy/status/2083749667410727319
1•delichon•44m ago•0 comments

Canadians are leaving the country at record levels. Can anyone solve this?

https://thehub.ca/2026/04/03/can-anyone-solve-canadas-brain-drain-problem/
1•TMWNN•44m ago•0 comments

Simple Outlier Detection in a Kalman Filter

https://gurevich.ca/simple-outlier-detection-in-a-kalman-filter/
1•gregsadetsky•52m ago•0 comments

Futurism says Meta has "almost nothing" to show for AI. The numbers say

https://runtimewire.com/article/futurism-says-meta-has-almost-nothing-to-show-for-ai-the-numbers-...
3•ryanmerket•54m ago•6 comments

AI Models as Commodities

https://www.axios.com/2026/08/01/deepseek-model-cheap-ai-price-war
1•kooi•59m ago•1 comments

Play Neuromancer

https://archive.org/details/msdos_Neuromancer_1988
1•mindcrime•1h ago•0 comments

OpenAI's claimed disproof of Connes' Rigidity Conjecture is invalid [pdf]

https://philarchive.org/archive/NIEWTCv17
23•muglug•1h ago•4 comments

Foundational ternary-model inference and training – CUDA, CPU, BitNet/TQ

https://github.com/Quitetall/tritium
1•jacquesm•1h ago•0 comments

Windows XP Original

https://archive.org/details/windows-xp-all-sp-msdn-iso-files-en-de-ru-tr-x86-x64
1•shrikaranhanda•1h ago•1 comments

ModRetro M64 – Nintendo 64 that plays original cartridges with 4K HDMI

https://modretro.com/products/m64
1•dazzatron•1h ago•0 comments

Task Hounds – a local-first, inspectable multi-agent dev workspace

https://github.com/catowabisabi/task-hounds
1•enomars•1h ago•0 comments

Show HN: I get 25 deep researched ideas with one single prompt

https://github.com/ringlochid/banksia
5•ringlochid•1h ago•2 comments

Large language models can predict the results of social science experiments

https://www.nature.com/articles/s41586-026-10742-x
1•Tomte•1h ago•0 comments

Show HN: CleanSlate – an open-source coding agent for the IDE, CLI, and SDK

https://github.com/TheWariend/CleanSlate
1•maaaz7n•1h ago•0 comments

AI Marketing

https://www.lerobit.com
1•akliluart•1h ago•0 comments

The teenage hitmen recruited to kill across Europe

https://www.bbc.com/news/articles/czrjyevmv61o
39•1659447091•1h ago•17 comments

Ask HN: Do Something about Bots

3•gregdaniels421•1h ago•4 comments

MkLinux and the pimped-out Apple Workgroup Server 9150

http://oldvcr.blogspot.com/2026/08/mklinux-and-pimped-out-apple-workgroup.html
22•goldenskye•1h ago•1 comments