Search found 68 matches

by sjhillier
Sat May 30, 2020 9:14 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 225
Replies: 1
Views: 181

Re: Problem 225

Yes.
by sjhillier
Fri May 15, 2020 3:58 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 329
Replies: 18
Views: 6053

Re: Problem 329

is it right to assume that the events "nth croak equals Xn", where Xn in {P, N}, are stochastically independent? I'm not sure I entirely understand the question, but I think the answer is "No". Let's put it this way. If the frog started near the small numbers (around 5 say), the density of primes t...
by sjhillier
Fri May 15, 2020 3:42 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 284
Replies: 7
Views: 2595

Re: Problem 284

I am finding 9 results I won't tell you the values, but I will confirm that you are correct that you are missing some solutions. If your original solution isn't working, try it a different way (another language or method) and you might find them, the solution space is not so large for this range.
by sjhillier
Fri May 15, 2020 3:28 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 315
Replies: 29
Views: 9049

Re: Problem 315

hamsterofdeath wrote:
Wed May 06, 2020 10:58 pm
i also tried a few numbers and confirmed the result manually. everything seems to be correct.
We prefer not to give out more test cases. Given that it sounds as if your individual calculations are correct, perhaps it's something different - eg the prime number algorithm.
by sjhillier
Sun Mar 08, 2020 9:35 pm
Forum: News, Suggestions, and FAQ
Topic: Sort threads in forum by Kudos given
Replies: 2
Views: 1188

Re: Sort threads in forum by Kudos given

It's still there for me, hopefully for you too. Click on the gold star in the top right corner of the problem thread.
by sjhillier
Fri Mar 15, 2019 9:00 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 483
Replies: 1
Views: 1030

Re: Problem 483

Edited values out of above post and send PM.
by sjhillier
Wed Feb 27, 2019 10:59 am
Forum: Clarifications on Project Euler Problems
Topic: Problem 008
Replies: 102
Views: 26033

Re: Problem 008

Thanks, post moved as suggested. In terms of an answer, your alternative wording might indeed be better, but personally I'm reluctant to change the wording of a problem that has been around for so long. The older the problem, the more the wording should stand I feel, unless it really is misleading, ...
by sjhillier
Sun Jan 21, 2018 8:17 pm
Forum: Recreational
Topic: Winning Lottery with Prime Number!?
Replies: 8
Views: 10676

Re: Winning Lottery with Prime Number!?

Interesting talk. For fun, some years ago (20ish!) I did a very naive analysis of the UK lottery to try to determine popular numbers. My results were not very strong, but there was certainly some indication of 1-30 being more popular. However, I noticed another trend that might be worth exploring. A...
by sjhillier
Sun Dec 31, 2017 7:17 pm
Forum: News, Suggestions, and FAQ
Topic: Statistics on problems solved so far
Replies: 19
Views: 8900

Re: Statistics on problems solved so far

However, as of today, the count concerning the one 100% problem I have solved so far has disappeared (it was still there yesterday). Could it be that the way non-finalised difficulties are handled may have changed since yesterday? Or perhaps it is a bug? Yesterday, the table reported 18 available p...
by sjhillier
Fri Dec 29, 2017 8:00 pm
Forum: Number
Topic: Prime generation
Replies: 3
Views: 8537

Re: Prime generation

What you have got there are 4 of the lucky numbers of Euler. The others are the rather more trivial smaller values. It has indeed been proved that no larger numbers of this type exist, but I suspect the proof is not so easy. A simpler insight into why this should be would be interesting.
by sjhillier
Sat Dec 16, 2017 10:51 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 616
Replies: 16
Views: 3205

Re: Problem 616

v6ph1 wrote:
Sat Dec 16, 2017 8:33 pm
On my reading, there is no creative number, which can generate all integers >1.
If it makes you feel better, I took about two days to convince myself that the answer was not 0. (I did have real work to do at the time too, or I might have been a bit quicker.)
by sjhillier
Fri Dec 15, 2017 10:39 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 287
Replies: 14
Views: 4602

Re: Problem 287

I think you're right that if you were using this as a genuine image encoding scheme, you'd also have to specify the size, which is not contained in the code itself as described here. However, for the purposes of this problem, we do know N, so the problem is completely determined, even if the encodin...
by sjhillier
Sat Dec 09, 2017 2:48 pm
Forum: News, Suggestions, and FAQ
Topic: About correct form of output
Replies: 3
Views: 1129

Re: About correct form of output

In those cases I believe 00012345 and 1.23450 would be correct.

I hope I'm not giving away too much (though it does provide a small amount of extra information) to say that whenever possible, we do try to avoid these sorts of circumstances that are likely to lead to answer formatting difficulties.
by sjhillier
Sat Dec 02, 2017 9:54 pm
Forum: News, Suggestions, and FAQ
Topic: Difficulty Rating for New Problems
Replies: 20
Views: 4113

Re: Difficulty Rating for New Problems

philiplu wrote:
Sat Dec 02, 2017 9:34 pm
Hmm, I guess that means Poohsticks Marathon, Problem 589 (View Problem) was supposed to be easy, given the standard posting cadence?
If it makes you feel better, I did assess this one as Medium, but was out-voted. It's one of those that depends on you having mastered a technique from earlier in the problem set.
by sjhillier
Fri Dec 01, 2017 3:10 pm
Forum: News, Suggestions, and FAQ
Topic: Difficulty Rating for New Problems
Replies: 20
Views: 4113

Re: Difficulty Rating for New Problems

Interesting discussion. I would like to suggest 450 as another under-estimate. From it's position in the sequence, it must have been rated Medium, but turned out to be one of the hardest. I have a particular liking of this problem, since it was my first time in the top 100 (three months after its re...
by sjhillier
Sun Nov 05, 2017 11:41 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 041
Replies: 25
Views: 7032

Re: problem 41

ethereal1m wrote:
Tue Aug 08, 2017 5:33 pm
I got

Code: Select all

98765431
from my calculation but it's wrong.
This answer is wrong as an 8 digit pandigital number must consist of the digits 1-8.
by sjhillier
Thu Jun 08, 2017 7:38 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 353
Replies: 10
Views: 5042

Re: Problem 353

MuthuVeerappanR wrote:
Thu Jun 08, 2017 2:34 pm
Thanks sjhillier. I solved it yesterday. Turns out one of my assumptions only fails for the k = 8 case.
I'm sure I made the same mistake too.
by sjhillier
Thu Jun 08, 2017 2:33 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 261
Replies: 26
Views: 8005

Re: Problem 261

Thierry, your post has been edited, and I've sent you a PM.
by sjhillier
Thu Jun 08, 2017 2:13 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 353
Replies: 10
Views: 5042

Re: Problem 353

Well you certainly have to be precise, but no more so than many other problems. There are other possible error modes, but it would be wrong to say more.
by sjhillier
Thu May 25, 2017 7:25 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 604
Replies: 3
Views: 2085

Re: Problem 604

dgokman wrote:
Thu May 25, 2017 1:54 am
Can someone confirm if F(28) = ??????
This is far too early for additional test values.