Search found 62 matches

by traxex
Fri Apr 27, 2018 5:57 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 493
Replies: 5
Views: 1478

Re: Problem 493

The problem statement is absolutely clear to me. I don't understand what you mean by the differents variations you list. I don't think there is a correct forum for discussing unsuccessful solution attempts, but if you've looked up the solution already then you can make a post in the closed forum wit...
by traxex
Fri Apr 20, 2018 4:57 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 084
Replies: 27
Views: 6547

Re: Problem 084

To be fair, there are many different probabilities posted in the closed forum. Many solvers had different interpretations of some details and had to do some guesswork. I remember very clearly that I could not reproduce the probabilities given in the problem and I did find the problem a bit frustrati...
by traxex
Mon Apr 16, 2018 3:30 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 437
Replies: 4
Views: 913

Re: Problem 437

KING-OLE wrote:
Mon Apr 16, 2018 1:49 pm
Must fpr<p?
Yes, you may assume that a primitive root modulo $p$ is less than $p$.
KING-OLE wrote:
Mon Apr 16, 2018 1:49 pm
If so, for p<10000, the only solution I get is the one shown as the example, where p=11 and fpr=8.
You should be able to find many examples with an exhaustive brute force search.
by traxex
Fri Apr 13, 2018 2:10 am
Forum: News, Suggestions, and FAQ
Topic: Organize / Display type of problem
Replies: 9
Views: 630

Re: Organize / Display type of problem

On another website that I visit regularly I had to resort to a custom CSS rule to *hide* tags that are everywhere spoiling my fun. traxex, Would you be willing to share the address of that website, please? It's http://www.spoj.com/. Edit: One of the top Eulerians , Min_25, has created some very nic...
by traxex
Thu Apr 12, 2018 8:29 am
Forum: News, Suggestions, and FAQ
Topic: Organize / Display type of problem
Replies: 9
Views: 630

Re: Organize / Display type of problem

Problem 345 (https://projecteuler.net/problem=345) is clearly a Grid / Matrix type problem and telling that wouldn't help in any way. I think that's because "Grid / Matrix" is such a vague category that it would not be very interesting. Similar websites that do use tags might have ones for linear a...
by traxex
Fri Apr 06, 2018 9:40 pm
Forum: News, Suggestions, and FAQ
Topic: Errors/Warnings/Bugs
Replies: 462
Views: 65600

Re: Errors/Warnings/Bugs

So it seems, sorry for the noise!
by traxex
Fri Apr 06, 2018 8:03 pm
Forum: News, Suggestions, and FAQ
Topic: Errors/Warnings/Bugs
Replies: 462
Views: 65600

Re: Errors/Warnings/Bugs

The recent problems page used to have a message at the top saying "Problem xyz will be published in H hours, M minutes" when a new problem was near. Problem 624 is coming soon, but I don't see this message. I think it was very useful for people in different timezones. The News page says that 624 is ...
by traxex
Wed Mar 28, 2018 6:46 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 333
Replies: 11
Views: 3295

Re: Problem 333

Jochen_P wrote:
Wed Mar 28, 2018 6:24 pm
my result for P(q)=1 for q<100 is 228 (instead of 233) :shock:
Perhaps you are missing two small primes that sum to 5? :D
by traxex
Mon Mar 26, 2018 9:49 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 623
Replies: 17
Views: 1211

Re: Problem 623

Can you please give the lambda-calculus representation for each of the four lines of code? They were meant to explain why $(\lambda x{.}(\lambda y{.}(xy)))$ and $(\lambda x{.}(\lambda x{.}(xx)))$ are not $\alpha$-equivalent, but $(\lambda x{.}(\lambda y{.}(yy)))$ and $(\lambda x{.}(\lambda x{.}(xx)...
by traxex
Sun Mar 25, 2018 11:43 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 623
Replies: 17
Views: 1211

Re: Problem 623

Sardaai wrote:
Sun Mar 25, 2018 11:29 pm
Should we assume that there are inherent delimiters around each variable name?
Yes, that is one way to put it. The $\Lambda(35)$ value given is also big enough to confirm that two adjacent variables do not cause ambiguity in parsing.
by traxex
Sun Mar 25, 2018 8:45 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 623
Replies: 17
Views: 1211

Re: Problem 623

Scoping in lambda calculus works very much like in C-family languages. Consider these two lines of pseudo-code: { string x = "foo"; { string y = "bar"; print(x, y); } } { string x = "foo"; { string x = "bar"; print(x, x); } } They are not equivalent, because the first one prints "foo bar" and the se...
by traxex
Sun Mar 25, 2018 7:00 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 623
Replies: 17
Views: 1211

Re: Problem 623

hexadoodle wrote:
Sun Mar 25, 2018 6:55 pm
Why is (Lx.(Lx.x)) not listed as a possibility in the table?
It's alpha-equivalent to (Lx.(Ly.y)).
hexadoodle wrote:
Sun Mar 25, 2018 6:55 pm
Would ((Lx.x)(Lx.x)) be alpha-equivalent to ((Lx.x)(Ly.y))?
Yes.
by traxex
Thu Mar 15, 2018 5:35 am
Forum: Programming languages
Topic: CAN MATLAB SOLVE THESE PROBLEMS
Replies: 4
Views: 1372

Re: CAN MATLAB SOLVE THESE PROBLEMS

MuthuVeerappanR wrote:
Thu Mar 15, 2018 4:08 am
lately many problems seems solvable-within-a-minute in C, C++ mostly.
Can you give some examples?
by traxex
Tue Mar 06, 2018 6:00 pm
Forum: Combinatorics
Topic: BBC Article - Lego arrangements
Replies: 1
Views: 906

Re: BBC Article - Lego arrangements

A web search for the number came up with this page: http://www.math.ku.dk/~eilers/lego.html#howgetright.
by traxex
Tue Mar 06, 2018 11:32 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 259
Replies: 18
Views: 5255

Re: Problem 259

The problem can be solved very comfortably in under 10 seconds. It doesn't require a scary amount of computation. I think there are multiple reasonable ways to count distinct expressions that lead to different results. I saw only one count in the dedicated thread and it differs from yours, but you c...
by traxex
Mon Mar 05, 2018 8:59 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 209
Replies: 20
Views: 5475

Re: Problem 209

I'm not sure if harryh is still with us but can anyone please confirm that, in harryh's 2-bit input example, where I think that last sentence was intended to read ..... the required property is not true....., I think the sentence is correct the way it's written. The property in question is "T(a, b)...
by traxex
Sat Mar 03, 2018 1:44 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 259
Replies: 18
Views: 5255

Re: Problem 259

vamsikal3 wrote:
Sat Mar 03, 2018 10:05 am
Is 123456789 a valid reachable number?
Yes, it is.
by traxex
Thu Mar 01, 2018 6:53 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 129
Replies: 13
Views: 2520

Re: Problem 129

vjcinjr wrote:
Thu Mar 01, 2018 4:59 pm
I understand "A(7) = 6" because the divisors of R(6) is the smallest repunit where 7 is a divisor.

Is it also true that A(13) = 6 because 13 does not appear as a divisor in any smaller repunit?
Yes. Similarly, A(3) = A(37) = A(111) = 3.
by traxex
Thu Feb 22, 2018 12:12 pm
Forum: News, Suggestions, and FAQ
Topic: Errors/Warnings/Bugs
Replies: 462
Views: 65600

Re: Errors/Warnings/Bugs

That's interesting. Perhaps there was an issue with some specific browser version in the past?

I noticed that you made the change already, thanks a lot! I visit Project Euler from shared or public computers quite often and being able to read the overviews without downloading them is nice.
by traxex
Wed Feb 21, 2018 10:35 am
Forum: News, Suggestions, and FAQ
Topic: Errors/Warnings/Bugs
Replies: 462
Views: 65600

Re: Errors/Warnings/Bugs

I prefer displaying PDF files in my browser instead of downloading them. However, the PDF overviews are served with a HTTP header that instructs the browser to download the file, forcing me to open it manually and cluttering my downloads. The header causing this is: Content-Disposition: attachment; ...