Search found 539 matches

by jaap
Fri Dec 20, 2019 5:23 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 027
Replies: 25
Views: 5960

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: 5960

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: 2
Views: 253

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: 572

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 7:39 am
Forum: News, Suggestions, and FAQ
Topic: Errors/Warnings/Bugs
Replies: 527
Views: 110227

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 ...
by jaap
Thu Jun 27, 2019 9:03 am
Forum: Discrete Mathematics
Topic: The Satisfiability Problem... NP or P?!
Replies: 4
Views: 2830

Re: The Satisfiability Problem... NP or P?!

https://medium.com/swlh/the-boolean-satisfiability-problem-solved-48ceb5550115 It is badly explained, and is certainly not a proof. It ends with: Considering that it is able to find a solution in most indices, as it usually works with a high probability (80%) then you can always try another index t...
by jaap
Tue May 28, 2019 12:44 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 672
Replies: 3
Views: 4308

Re: Problem 672

Thanks for fixing that hk. Shouldn't there be a floor function around the $\frac{7^K-1}{11}$ term? I don't think there is a universally accepted meaning for a sum where the upper limit for the index variable is not an integer. Please investigate if $\frac{7^K-1}{11}$ isn't an integer for the values ...
by jaap
Tue May 28, 2019 11:35 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 672
Replies: 3
Views: 4308

Problem 672

Is "no nothing" a typo for "do nothing"?

Shouldn't there be a floor function around the $\frac{7^K-1}{11}$ term? I don't think there is a universally accepted meaning for a sum where the upper limit for the index variable is not an integer.
by jaap
Mon May 27, 2019 12:40 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 671
Replies: 3
Views: 3333

Re: Problem 671

I have not solved this question yet, but have worked out F_4(3) on paper. @amagri: I believe those are indeed forbidden, so for both those reasons you cannot use a 1x3 tile when n=3. @MuthuVeerappanR: I think rotations around the axis of the loop are not considered different. I get 24+24+24+24+8 = 1...
by jaap
Mon May 20, 2019 12:31 am
Forum: News, Suggestions, and FAQ
Topic: Recover account
Replies: 4
Views: 3073

Re: Recover account

hk wrote:
Sun May 19, 2019 11:55 am
I looked up your account:
Last Visit:

Saturday, 19th May 2018, 11:11 pm
So it seems that you remembered your password after all.

(usually people find out their password after some head scratching.)
It is 2019 now, you know.
by jaap
Fri May 17, 2019 5:36 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 647
Replies: 2
Views: 2986

Re: Problem 647

I know that quite some folk have solved this one already and it doesn't look too daunting, really - except that: well I'm getting 186 and not 184 as result for F_3(100). It really is 184. If you want, you can send me the pairs (A,B) that make up the sum by private message (you should have only four...
by jaap
Sat Mar 16, 2019 8:59 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 600
Replies: 1
Views: 722

Re: Problem 600

RichardDL wrote:
Sat Mar 16, 2019 4:13 pm
18, 5, 1, 4, 3, 3, 2
18, 5, 2, 3, 3, 4, 1
Hexagons that are mirror images of one another are congruent.
by jaap
Wed Mar 06, 2019 4:21 pm
Forum: News, Suggestions, and FAQ
Topic: Project Euler Style Sheet Update
Replies: 33
Views: 10233

Re: Project Euler Style Sheet Update

First, I don't know how to switch from the dark theme to light or vice versa. Is this missing, hidden, or am I just blind? In the Account tab, there is a section with Country, Language etc, including Theme. Change the Theme from Dark to Default (and click the Update Details button) to go back to wh...
by jaap
Mon Mar 04, 2019 9:30 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 425
Replies: 28
Views: 7230

Re: Problem 425

pxor wrote:
Mon Mar 04, 2019 4:03 am
Hey, could anyone explain how is 503 connected to 2?
503 is connected to 103, and the rest is via the chain given as an example in the problem:
2 ↔ 3 ↔ 13 ↔ 113 ↔ 103 ↔ 503
by jaap
Wed Feb 20, 2019 10:57 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 656
Replies: 9
Views: 1687

Re: Problem 656

In the wording of the problem, I don't think it is a good idea to use the letter n for two different variables - first as the index of the sequence, then as an element of T. I think it would be better to change the second use to a variable named t for example.
by jaap
Sat Jan 12, 2019 10:00 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 196
Replies: 34
Views: 10897

Re: Problem 196

tchiari wrote:
Sat Jan 12, 2019 6:53 pm
I'm wondering if someone would be willing to give me a prime that is part of a triple but not on my list. That would help me to figure out if the issue is with how I'm generating/determining my primes or with how I'm looking for triples.
I've sent a private message.
by jaap
Mon Dec 24, 2018 5:49 am
Forum: News, Suggestions, and FAQ
Topic: Hairsplitting Curiosity (w/ Alliteration)...
Replies: 6
Views: 2130

Re: Hairsplitting Curiosity (w/ Alliteration)...

https://projecteuler.net/about=aliases If you hover over a poster's name in a solution thread (specifically the ones that are in italics, which indicates it is an alias), you will see a tooltip showing the account username. Unfortunately the quoting system always seems to display the username, not i...
by jaap
Sat Dec 15, 2018 5:48 am
Forum: Discrete Mathematics
Topic: Sorting...
Replies: 4
Views: 5825

Re: Sorting...

You have re-invented the Pigeonhole sort.

The wiki page on sorting algorithms has a separate section for non-comparison integer sorts like this. Its main disadvantage is that its running time and its memory requirements depend on max, not just on n.
by jaap
Fri Nov 16, 2018 3:47 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 351
Replies: 17
Views: 8828

Re: Problem 351

If you ever need more than, say, 600MB of data, then you are probably doing it wrong. You are either using the wrong solving method, or maybe you just don't need to have all of that data in memory at the same time.