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Comment by JohnKemeny | Hacker News Reader

It's that time of year again. I like A* as much as the next one, but it seems a bit excessive a times.

Title should have a (2014) in it: Introduction to the A* Algorithm (2014).

1 points, 8 months ago, 1 comments: Introduction to the a* Algorithm (https://news.ycombinator.com/item?id=41897736)

202 points, 3 years ago, 30 comments: Introduction to the A* Algorithm (2014) (https://news.ycombinator.com/item?id=30287733)

4 points, 5 years ago, 1 comments: Introduction to the a* Algorithm (https://news.ycombinator.com/item?id=24146045)

201 points, 7 years ago, 14 comments: Introduction to A* (2014) (https://news.ycombinator.com/item?id=18642462)

5 points, 7 years ago, 0 comments: Introduction to A* (https://news.ycombinator.com/item?id=16190604)

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Please consider some folks might be new to A*, and perhaps even HN, so maybe this is the first time they’ve seen it! :)

Also, I have ten books on perspective drawing, and my understanding isn’t complete without all ten of them

Or, if I’m teaching a subject on A*, perhaps ONE of those articles conveys the materials best for my students.

Thank you for providing links to the others though! I’m sure it will be helpful for someone.

Yeah people live by this leaky abstraction that an article having been posted before means everyone was online that day and saw it and now it has expired. And for some reason they chase these hall monitor points for pointing it out. Let's see what a discussion would be like from today's point of view.

The cheapest available model once you have Theory of Mind (the idea that the other things in the environment might be thinking like you do) is that they're you again.

The Smarties test (What's in this Smarties tube - look it's not Smarties, ok now what does somebody else think is in the tube?) shows that humans need a further step to discover that model isn't enough.

But it's still cheaper and it's pretty good. It will correctly predict that this person you've never met before probably wants cake not death, just like you. It won't reliably predict whether they prefer lemon cake or coffee cake. But it's a good first guess.

Also: some people seem to get an amount of pleasure from pointing out repeats, as if remembering that something was posted before is knowledge enough to make them a better person than the poster, us all, or just the person they thought they were themselves. This is fine when something is posted far too often, or is reposted by a point-farming bot (presumably the users running such bots hope to use the reputation of the account somehow in future), but is often done overzealously.

I agree, though to be a pedant:

> perhaps ONE of those articles

It is the same article each time, though the comments coming off the different postings of it might have unique nuggets of useful information to dig for.

> Thank you for providing links to the others though! I’m sure it will be helpful for someone.

It isn't as prominent as on other sites, so it isn't difficult to miss sat right at the bottom of the main page, but HN does have a working search function. I find searching for older posts this way can be quite useful for the above reason, when something comes up that has existed for a few years.

Personally, I don’t bother searching because I only consume the headlines, on other news sites too, come to think of it. There’s lots of interesting things people post but frankly I’d rather pay for a good book on any subject.

hides from the dreaded downvoters

I used to spend more time browsing when reading an actual newspaper or magazine. The discourse on opinion pieces and such is more thought out too—many people, myself included, post too quickly before thinking because we’re always on the go.

Something about the online experience consuming news is less satisfying. Perhaps a hacker out there can set up a print version of HN archives, and print it on a Gutenberg Press. :)

I wish there was a “evergreen” feature for social sites where it tracked resubmissions and would auto suggest them to people who haven’t seen them and periodically surface them to those who have and ask “is this still relevant” That way really good content keeps being recommended to those who need it and you get fewer complaints from old timers who don’t have to see it N times.

My dream is a knowledge-aware Wikipedia that can be more relevant by understanding what the reader knows, might know and might find interesting w/o being overwhelming. I guess you can make this social too and have discussion groups, but it's already too large of a project in my mind.

> Also, I have ten books on perspective drawing, and my understanding isn’t complete without all ten of them

Which books might those be? ;)

I think A* deserves the popularity. It’s a simple variation on depth-first and breadth-first graph traversal that everyone learns in CS101, massively useful in some situations, yet for some reason isn’t a standard part of CS education. It’s a marvelous thing the first time you learn about it.

It’s even more marvelous if it helps you recognize that the difference between BFS and DFS is how you pick the next node to explore out of your bag of unexplored nodes. That symmetry is easily lost if DFS is only taught as a recursive algorithm.

Let it keep coming up every couple years to marvel a new generation of programmers.

I was surprised to see this article because it's not that time of year. Typically A* shows up around December, because people discover it via Advent of Code. (And that's the only place I've used it.)

I think it's just the first, most obvious thing to teach people just starting in pathfinding. It works in real life, it's easy to visualize and compute. Therefore all the tutorials are about it :)

I think the real reason this article keeps coming back is how good it is at teaching through examples and visualization, rather than the A* algorithm itself.

There are a lot of people on HN that aren't you.

How could the OP submit this link anyway?

When I submit a link that has been posted on HN before, it just redirects me to the old post.

Maybe there's a secret guide on how to build up karma :))

Please think of all the lucky few. (xkcd 1053)

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