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Why Rocq is better than Lean for program verification

https://joomy.korkutblech.com/posts/2026-07-28-why-rocq-is-better.html
1•birdculture•18s ago•0 comments

LLM Honeypot

https://llm2human.pages.dev/
1•8thom•52s ago•0 comments

Swift on Windows: A Year of Refinement

https://speakinginswift.substack.com/p/swift-on-windows-a-year-of-refinement
1•wrxd•4m ago•0 comments

CherryTree Note Taker App

https://www.giuspen.net/cherrytree/
1•theMezz•5m ago•1 comments

Show HN: An AI Color Grader – Pico

https://www.perbhat.com/pico
1•perbhat•8m ago•0 comments

Microsoft keeps capex unchanged, the only datacenter giants to hold AI spending

https://www.businessinsider.com/microsoft-ai-capex-unchanged-data-centers-spending-tech-giants-20...
2•mapping365•8m ago•0 comments

Rogue OpenAI agent that hacked startup tried to attack other firms

https://www.theguardian.com/technology/2026/jul/29/rogue-openai-agent-that-hacked-startup-tried-t...
3•jethronethro•8m ago•0 comments

How HN: Vetted Startup – discover, buy, and sell startups with verified revenue

https://vettedstartup.com/
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Chip stocks shed more than $1T as selloff hits AI companies

https://www.cnbc.com/2026/07/29/chip-selloff-sk-hynix-samsung-softbank.html
1•yogthos•10m ago•0 comments

Why agentic systems need ontologies [video]

https://www.youtube.com/watch?v=Sir59K8ZDPU
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Arizona's Declining Groundwater

https://science.nasa.gov/earth/earth-observatory/arizonas-declining-groundwater-154567/
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TrustZone Intermezzo: Broken OP-Tee Memory Isolation on I.mx 8M

https://sigma-star.at/blog/2026/06/trustzone-intermezzo/
1•lengfeld•17m ago•0 comments

PyTorch Tutorial for Deep Learning

https://blog.jetbrains.com/pycharm/2026/07/pytorch-tutorial-for-deep-learning/
1•smokeeaasd•18m ago•0 comments

Copilot code review: Agent skills and MCP now generally available

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More than 12M eye drops recalled contamination could harm vision

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Three Virtues by Larry Wall

https://thethreevirtues.com/
3•gregsadetsky•24m ago•0 comments

GitHub is the wrong shape for this new world

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Show HN: Always on visual context for your agents

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2•quantbagel•25m ago•0 comments

It was surprisingly hard to break CloudNativePG replication

https://coroot.com/blog/fencing-a-cnpg-replica/
2•valyala•26m ago•0 comments

Vector AI Agent

https://routinehub.co/shortcut/24957/
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The task is not the job

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Show HN: I built a Chrome extension so Claude can close my 300 tabs

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Ask HN: Is everybody's Claude weekly quota reset time the same?

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Òrbites – el puzzle de les constel·lacions

https://orbites.cat/
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Microsoft Struggling with AI-Discovered Security Bugs

https://www.propublica.org/article/anthropic-mythos-microsoft-software-vulnerabilities
3•donohoe•33m ago•0 comments

AgentSwarms – self-hostable agentic AI/BI platform with sandboxed Python (ELv2)

https://github.com/AgentSwarms-fyi/agentswarms
3•agentswarms•37m ago•0 comments

The Hunt for the Counterfeiter Trying to Make the Perfect Bill

https://www.nytimes.com/2026/07/16/magazine/counterfeit-dollars.html
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Agentic Design

https://agentic-design.ai
2•Davcker•38m ago•0 comments

Marvelous – A Markdown editor where every save is a Git commit

https://github.com/stevenjjobson/marvelous
1•stevenjobson•41m ago•1 comments

Ireland unveils blueprint to electrify economy by 2050

https://www.euronews.com/my-europe/2026/07/29/ireland-unveils-blueprint-to-electrify-economy-by-2050
11•devonnull•41m 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.