Search found 551 matches

by jaap
Tue May 04, 2021 4:56 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 756
Replies: 6
Views: 130

Re: Problem 756

Uniformly distributed refers to the probability distribution, and means that when the m-tuple is chosen at random, every possible outcome is equally probable. See Uniform Distribution . Of course, you randomly choose only from the set of valid m-tuples (i.e. it must have m integers that are strictly...
by jaap
Fri Apr 30, 2021 1:16 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 147
Replies: 12
Views: 5722

Re: Problem 147

They are not sub-grids of each other. The question just asks you to examine one grid of each possible size up to some maximum size limit, and add their results together.
by jaap
Thu Mar 11, 2021 2:04 pm
Forum: Number Theory
Topic: Calculating modular inverses of p mod $2^p$
Replies: 2
Views: 888

Re: Calculating modular inverses of p mod $2^p$

After some experimentation it turns out that if $p=2k+1$ then the inverse of $p$ mod $2^p$ is $\frac{k\cdot2^p + 1}{p}$. Clearly if that fraction is actually an integer, then it works as the inverse of $p$ mod $2^p$. To prove that it is an integer for prime $p$, you can use Fermat's little theorem (...
by jaap
Wed Mar 10, 2021 9:43 pm
Forum: News, Suggestions, and FAQ
Topic: How do I toggle Dark Mode?
Replies: 2
Views: 294

Re: How do I toggle Dark Mode?

In the Account tab scroll down to the section with Location/Language/Time Zone etc., change the Theme from Default to Dark or vice versa, and click the Update Details button.
by jaap
Sun Nov 29, 2020 10:05 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 273
Replies: 37
Views: 15780

Re: Problem 273

There's an 's' missing in 'integer' in the first line of the problem statement. And the same missing 's' in the same word on line 4. You could add an s, but it is also correct as is, since integer is being used here as an adjective rather than a noun (like "whole" instead of "whole n...
by jaap
Thu Nov 05, 2020 8:57 am
Forum: News, Suggestions, and FAQ
Topic: Idea for new Archives display filter
Replies: 11
Views: 1596

Re: Idea for new Archives display filter

You can currently filter the archives by All/Solved/Unsolved/Pinned. Any chance of adding a filter for problems which have a new forum post within the past day? You can already see those in the past day by the coloring, but it would be nice to collect them all tightly, rather than looking through 1...
by jaap
Thu Sep 24, 2020 2:33 pm
Forum: News, Suggestions, and FAQ
Topic: Errors/Warnings/Bugs
Replies: 626
Views: 214871

Re: Errors/Warnings/Bugs

Two minor irritations: 1. When you select and copy/paste the text of a PE problem, the MathJax is not selected and copied. I like to put the problem into a code comment at the top of my program for the problem, and that is more work now. It used to mostly copy the maths text, except for some weirdne...
by jaap
Fri Jul 24, 2020 8:37 am
Forum: News, Suggestions, and FAQ
Topic: Errors/Warnings/Bugs
Replies: 626
Views: 214871

Re: Errors/Warnings/Bugs

Hi, I am having trouble opening the thread for Problem 497. Chrome would load a few posts but when I scrolled down further, it became just a blank screen. Maths formulas were not rendered and code sections would not open. Thank you for reporting this. I cannot load the thread either: the Chrome tab...
by jaap
Tue Jun 30, 2020 2:51 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 059
Replies: 114
Views: 48400

Re: Problem 059

Hi! I also have trouble in getting "an OK - problem solved" although I'm like TristenR am pretty sure I've solved it. However, counting up the entries in the original file - I only get 1454... which is contrary to TristenRs 1455. What is the correct number here (in the original text file)...
by jaap
Tue Feb 25, 2020 6:32 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 207
Replies: 8
Views: 5863

Re: Problem 207

...where $4^t$, $2^t$, and $k$ are all positive integers and $t$ is a real number. For any m ≥ 1 let P(m) be the proportion of such partitions that are perfect with k ≤ m . So there are two partitions, $4^1 = 2^1 + 2$ and $4^{1.5849625...} = 2^{1.5849625...} + 6$ with $k\le 6$, only one of which ha...
by jaap
Mon Feb 10, 2020 5:52 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 701
Replies: 3
Views: 2532

Re: Problem 701

701 "Consider the maximum area of connected cells." Nowhere is "maximum area" defined. It's just the literal meaning. The largest possible area of a connected set of (black) cells. Wouldn't the largest possible area be W x H, i.e. the given square with every square a black squar...
by jaap
Sun Feb 09, 2020 7:52 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 701
Replies: 3
Views: 2532

Re: Problem 701

Junglemath wrote: Sun Feb 09, 2020 6:36 pm Problem 701 (View Problem)

"Consider the maximum area of connected cells."

Nowhere is "maximum area" defined.
It's just the literal meaning. The largest possible area of a connected set of (black) cells.
by jaap
Mon Feb 03, 2020 6:49 am
Forum: Clarifications on Project Euler Problems
Topic: problem 065
Replies: 33
Views: 13145

Re: problem 065

whatteaux wrote: Sun Feb 02, 2020 11:18 pm
jaap wrote: Fri Jan 31, 2020 12:44 pm But it is surprising that e's continued fraction has a pattern to it at all.
Did you mmean Pi, rather than e? E's has a pattern (as shown in this thread), whereas Pi's is patternless.
I'm saying that you would not expect a pattern for e, so it is surprising that there is one.
by jaap
Fri Jan 31, 2020 12:44 pm
Forum: Clarifications on Project Euler Problems
Topic: problem 065
Replies: 33
Views: 13145

Re: problem 065

In the problem statement it lists 2k as one of the components of the continued fraction, but nowhere is it stated what k is. Help? It is just there to indicate that the pattern shown in the first numbers continues. It shows what an arbitrary section of the list would look like. Here are some other ...
by jaap
Fri Jan 31, 2020 9:31 am
Forum: Clarifications on Project Euler Problems
Topic: problem 065
Replies: 33
Views: 13145

Re: problem 065

In the problem statement it lists 2k as one of the components of the continued fraction, but nowhere is it stated what k is. Help? It is just there to indicate that the pattern shown in the first numbers continues. It shows what an arbitrary section of the list would look like. Here are some other ...
by jaap
Fri Dec 20, 2019 5:23 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 027
Replies: 25
Views: 11552

Re: Problem 027

If you'd care to elaborate on such a simple relationship @ PE.net, I would sure appreciate it, as I imagine Lucas-C would too... Take a look at hk's post on the first page of the problem's discussion forum. It shows the relationship between two solutions. If you plot all the related solutions (i.e....
by jaap
Thu Dec 19, 2019 10:31 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 027
Replies: 25
Views: 11552

Re: Problem 027

All the solutions on a parabola are related to each other in a very simple way. Given that the solution to the problem lies on such a parabola, it would be a spoiler to discuss it too much.
by jaap
Tue Dec 03, 2019 6:51 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 601
Replies: 3
Views: 1822

Re: Problem 601

I disagree. $k$ is essentially the length of the streak, i.e. how many consecutive lines in the two examples have divisibility before the line where it is no longer divisible. Like a lucky streak, it is about how long you can keep it going before your luck runs out. The divisibility by 1 is part of ...
by jaap
Wed Nov 20, 2019 4:19 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 689
Replies: 3
Views: 2143

Re: Problem 689

Thanks for the clarification. I'm still worried that f(x) may not be clearly defined. For example, the decimal fraction 1/2 has two binary representations: 0.1000... and 0.0111.... And those lead to f(1/2) = f(0.1000.. (base 2) ) = 1, and f(1/2) = f(0.0111.. (base 2) ) = π 2 /6 - 1. While these are...
by jaap
Fri Jun 28, 2019 8:39 am
Forum: News, Suggestions, and FAQ
Topic: Errors/Warnings/Bugs
Replies: 626
Views: 214871

Re: Errors/Warnings/Bugs

We cannot make two consecutive posts in the same solution forum. I think you should be able to edit your post and add the content in the same post. I think you misunderstood the problem. The post is not shown in the problem thread so it cannot be edited. Hopefully it is just a caching problem that ...