Comments URL: https://news.ycombinator.com/item?id=49539006

Points: 15

# Comments: 0

Comments URL: https://news.ycombinator.com/item?id=49036765

Points: 144

# Comments: 228

That is, until I checked the program I used for testing (which I didn't write), and found the following code:

  dealloc(this)
  return this->field

My allocator, however, overwrote the field during the deallocation with bookkeeping stuff, which meant the returned value was not what the programmer intended and after a short while the program crashed.

Unlike TFA, I had the luxury of just fixing the test program.

https://en.wikipedia.org/wiki/IKEA_effect

If the company puts an artificial proof of work demanding a rack of the latest data center GPUs, that should be illegal.

If the binary has the same hardware requirements that the company used when the service was up, I see it as totally fair.

Of course there'll be idiots, but I doubt you'll see a stronger backlash than to a company shutting down the servers without any solution, like they can do now.

As far as I understand that situation is accepted by the initiative. The requirement is not that it works on any specific hardware or software stack, just that it can theoretically work.

> a binary that can be used to create cheats against the next version of the product

Anti-cheat solutions aren't required to be released, and if there are bugs in the server, they might even be found and patched by the community.

Reading the process in TFA, it's very much dependent on the comprehensiveness of the testing framework. And apparently, the tests never built a lobby in the bottom left corner...

Anything else it didn't try, is probably also not documented and not implemented.

With the growing use of AI in reverse engineering, we might need to shift our goals to more strongly verifiable ones, such as matching decompilation.

As I understand it, B2 means one has a solid, functional proficiency in the language. They conversate/listen/read/write in diverse situations, without needing to switch to a different language or to prepare in advance.

They're very likely, however, to make mistakes, say things in non-idiomatic ways etc. although this is expected to be minor enough to not affect the ability to understand them.

In order to get to C1 and above, one needs a deeper understanding of the language - phrases, idioms, connotations, registers, etc. and a broader set of situations they can handle, e.g., a philosophical discussion. An of course, errors are expected to be rarer.

So, literally speaking, B2 is rather fluent, since the language is "flowing" out of them and they're not stopping to think every other word (which is, as far as I understand, a common interpretation of flüssig in German).

But as "fluent" speakers should know, words come with expectations beyond the literal meaning :P

I had an insight the other day, that as I fix the n least (and most, it's a palindrome!) significant decimal digits, I also fix the remainder from division in 5^n. Let's call it R. Since I also fix by that point a bunch of least (and most) significant bits, I can subtract how much they contribute mod 5^n from R, to get the remainder from division in 5^n of the still unknown bit. The thing is, maybe it's not possible to get this specific remainder with the unknown bits, because they're too few.

So, I can prepare in advance a table of size 5^n (for one or more ns) which tells me how many bits from the middle of the palindrome I need, to get a remainder of .

Then when I get to the aforementioned situation, all I need to do is to compare the number in the table to number of unknown bits. If the number in the table is bigger, I can prune the entire subtree.

From a little bit of testing, this seems to work, and it seems to complement my current lookup tables and not prune the same branches. It won't make a huge difference, but every little bit helps.

The important thing, though, is that I'm just happy there are still algorithmic improvements! For a long while I've been only doing engineering improvements such as more efficient tables and porting to CUDA, but since the problem is exponential, real breakthroughs have to come from a better algorithm, and I almost gave up on finding one.

[0] https://ashdnazg.github.io/articles/22/Finding-Really-Big-Pa...

After reading the article, though, I feel like I definitely need a superoptimiser, to see what could be improved :)

Note to website owner - it could be nice to have a permalink to the English version.

> The reason is that Starflight was written in Forth

I recently reverse-engineered another game from the 80's, and had a similar issue because it was written with Turbo Pascal.

The different tools didn't like quirks such as data stored inline between the instructions or every library function having a different calling convention.

Turns out the simplest way to handle this was to write my own decompiler, since Turbo Pascal 3 didn't do any optimisations.

Mostly silly posts about silly projects.