Search found 92 matches
- Tue Jan 30, 2024 2:49 pm
- Forum: Number
- Topic: Algorithm to determine a hidden attributes value
- Replies: 5
- Views: 514
Re: Algorithm to determine a hidden attributes value
Am I too stupid if I say that if you can check the sum for all the $\binom{100}{5}$ 5-objects subsets then you can build up a linear system of $\binom{100}{5}$ equations in $100$ variables? Not stupid, but you've fallen into a trap that's very easy to fall into. (I did too, and so did the person wh...
- Fri Nov 03, 2023 11:43 am
- Forum: Number Theory
- Topic: How to enumerate/count the numbers of a particular form below N in an efficient way?
- Replies: 11
- Views: 6354
Re: How to enumerate/count the numbers of a particular form below N in an efficient way?
My technique gives theoretical asymptotics of $O(N^{23/24})$ for $\{1,1,1,1\}$, which doesn't really seem practical. Since then I have figured out how to do it in $\tilde{O}(N^{2/3})$ using standard techniques: sum the multiplicative function which evaluates to $N$ at primes and $0$ at higher power...
- Thu Aug 24, 2023 12:44 pm
- Forum: News, Suggestions, and FAQ
- Topic: Suggestion - Expose API to public usage
- Replies: 1
- Views: 482
Re: Suggestion - Expose API to public usage
What API? A project which isn't designed with the goal of supporting application programmers doesn't necessarily have an interface for them to use. From what we can see, it's possible to infer that the site itself mainly accesses data dumps which are generated by a scheduled task rather than live da...
- Mon Aug 14, 2023 11:54 am
- Forum: News, Suggestions, and FAQ
- Topic: Copyright and commercial use
- Replies: 10
- Views: 2431
Re: Copyright and commercial use
Doesn't the history of open source software teach us that companies will ruthlessly exploit people's passion projects for profit whenever it's possible to do it without having to pay the people who actually did the work a cent? How many of the proliferation of software licences come from the reactio...
- Mon Aug 14, 2023 11:35 am
- Forum: News, Suggestions, and FAQ
- Topic: Problem notes
- Replies: 4
- Views: 4286
Re: Problem notes
I have a private "gist" on gist.github.com where I sketch partial results and ideas which need development. Obviously it's not an integrated UX, but it's an adequate means of accessing my thoughts on multiple devices without polluting my git repository of actual solutions.
- Fri May 19, 2023 7:41 am
- Forum: Clarifications on Project Euler Problems
- Topic: Problem 843
- Replies: 14
- Views: 764
Re: Problem 843: periods for n = 6 are {1, 2}
He does have a point. If it's a circle, it doesn't really have a beginning or end. If it has the same exact numbers in the same exact order, isn't it the same circle? No, it isn't. It may help to paint one of the buckets in a different colour to the rest to make an arbitrary fixed reference point.
- Mon Apr 17, 2023 9:32 am
- Forum: News, Suggestions, and FAQ
- Topic: Statistics improvement
- Replies: 4
- Views: 303
Re: Statistics improvement
You can find that out by going to Statistics / Locations.
- Fri Mar 10, 2023 12:15 pm
- Forum: News, Suggestions, and FAQ
- Topic: Security check gone?
- Replies: 8
- Views: 2363
Re: Security check gone?
There have been a few days when I've solved 5 problems, once within 6.5 hours. Starting fresh, I could probably knock off a lot of the first 50 very quickly. I don't think you need to worry about being banned for submitting a handful of answers an hour apart.
- Sat Dec 24, 2022 8:59 am
- Forum: Clarifications on Project Euler Problems
- Topic: Problem 808
- Replies: 2
- Views: 311
- Mon Nov 28, 2022 9:03 am
- Forum: News, Suggestions, and FAQ
- Topic: Errors/Warnings/Bugs
- Replies: 766
- Views: 258442
Re: Errors/Warnings/Bugs
It's probably not random: DB engines don't tend to randomise unless they're told it. I would guess that it's an artifact of the number of rows in the table. Wonder whether there's a PE question waiting to be written about unstable sorts and k-medians...
- Thu Nov 24, 2022 8:31 am
- Forum: News, Suggestions, and FAQ
- Topic: "Collapsibility" behaviour for code fragments
- Replies: 2
- Views: 178
Re: "Collapsibility" behaviour for code fragments
I mean, we invest time and effort into solving the challenges and probably want to make sure, as our only reward, that everyone sees and appreciates our beautiful code and ingenious solution at first glance Given the amount of write-only code that I see in the discussion threads, that can't be the ...
- Mon Nov 07, 2022 11:13 am
- Forum: Clarifications on Project Euler Problems
- Topic: Problem 086
- Replies: 81
- Views: 32146
Re: Problem 086
I think it's mainly there as a hint for people to sanity-check their approach. A candidate is a local minimum, up to symmetry of the cuboid. (You could argue that there are six candidates, but they come in symmetric pairs).
- Wed Oct 05, 2022 8:37 am
- Forum: News, Suggestions, and FAQ
- Topic: "History" tab suggestion
- Replies: 9
- Views: 501
Re: "History" tab suggestion
The obvious solution to the MathJax problem is to not truncate the titles in the source HTML but instead place them in a div with a fixed width and CSS overflow:hidden . I don't guarantee it will work in practice, but in theory it seems correct.
- Tue Sep 27, 2022 9:02 am
- Forum: News, Suggestions, and FAQ
- Topic: A tag that is always hidden on every problem
- Replies: 2
- Views: 199
Re: A tag that is always hidden on every problem
I am talking about a list of about 50 problems ( some of which I have solved , but most I haven't). Maybe you've already done this, but since you don't mention it: one next step would be to analyse the problems you have solved and see what the solutions have in common. Also, read their discussion t...
- Wed Sep 14, 2022 8:13 am
- Forum: News, Suggestions, and FAQ
- Topic: Problem 60 wrong answer?
- Replies: 3
- Views: 442
- Mon Aug 29, 2022 9:24 am
- Forum: Number Theory
- Topic: Tree of Eisenstein triples
- Replies: 3
- Views: 8837
Re: Tree of Eisenstein triples
We know that the primitive Pythagorean triples can be generated using (3,4,5) as a seed Or, indeed, using (0, 1, 1) as a seed, although the first layer of expansion is inelegant. (This seed is an eigenvector of one of the matrices, and the other two give the same expansion). (0, 1, 1) similarly ser...
- Sat Jul 30, 2022 12:26 am
- Forum: Resources
- Topic: The chess puzzle that led to a Fields Medal
- Replies: 6
- Views: 1244
- Fri Jul 29, 2022 8:56 am
- Forum: Resources
- Topic: The chess puzzle that led to a Fields Medal
- Replies: 6
- Views: 1244
Re: The chess puzzle that led to a Fields Medal
In particular, you can rearrange the squares to make a problem with an identical graph but where movement is king moves instead of knight moves: it's a row of 9 squares, a1 to i1, with the 10th square at d2. The white kings start at a1 and b1, and the black kings start at c1 and d2. This makes it mu...
- Tue Jun 14, 2022 7:41 am
- Forum: News, Suggestions, and FAQ
- Topic: Extra credit
- Replies: 2
- Views: 395
Re: Extra credit
Have you seen the existing flair feature?
- Mon Jun 06, 2022 11:18 am
- Forum: Clarifications on Project Euler Problems
- Topic: Problem 025
- Replies: 36
- Views: 15311
Re: Problem 025
@Liquid25677, I don't see a way to answer that question which doesn't include a major spoiler for this problem, so I suggest that you solve the problem and then see whether the discussion thread which you unlock answers your question.