Hi, For some reason, I can't login to my account. PE says 'Username not known'.

Can anyone let me know why this is happening?

## Search found 141 matches

- Sun Aug 25, 2019 6:34 pm
- Forum: News, Suggestions, and FAQ
- Topic: Username not known
- Replies:
**9** - Views:
**379**

- Wed Aug 21, 2019 2:55 am
- Forum: Clarifications on Project Euler Problems
- Topic: Problem 613
- Replies:
**9** - Views:
**2976**

### Re: Problem 613

It's just a mathematical description RishadanPort. To make it more abstract, if you randomly select a point inside a right angled triangle and randomly choose some direction to draw a line (starting from the point we chose), what is the probability that the line intersects the hypotenuse?

- Fri Jun 28, 2019 5:15 am
- Forum: News, Suggestions, and FAQ
- Topic: Errors/Warnings/Bugs
- Replies:
**524** - Views:
**102913**

### 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.

- Mon May 27, 2019 10:33 am
- Forum: Clarifications on Project Euler Problems
- Topic: Problem 671
- Replies:
**3** - Views:
**3153**

### Re: Problem 671

671 Hi All, Tiling which are identical after rotating the loop about its axis considered different? Only if I consider them different, I get F_4(3) = 104. Else am stuck at 92. I'm not sure whether 'reflecting horizontally or vertically would give a different tiling, these tilings are to be counted ...

- Mon May 06, 2019 8:17 am
- Forum: Clarifications on Project Euler Problems
- Topic: Problem 272
- Replies:
**14** - Views:
**8387**

### Re: Problem 272

Hi mdean,

If you could PM your value, I can confirm it.

If you could PM your value, I can confirm it.

- Tue Mar 05, 2019 4:43 pm
- Forum: News, Suggestions, and FAQ
- Topic: Project Euler Style Sheet Update
- Replies:
**33** - Views:
**9247**

### Re: Project Euler Style Sheet Update

The kudos count is aligned properly now. Kudos for that euler...

- Mon Mar 04, 2019 12:59 am
- Forum: News, Suggestions, and FAQ
- Topic: Project Euler Style Sheet Update
- Replies:
**33** - Views:
**9247**

### Re: Project Euler Style Sheet Update

Many thanks to the PE team for the new style. The site looks great with the new styling.

The only issue that I saw was as that of

Truly appreciate the hard work in getting PE a new style.

The only issue that I saw was as that of

**MHealy**. For non-permananent posts, the kudos are slightly mis-aligned in Chrome.Truly appreciate the hard work in getting PE a new style.

- Tue Nov 27, 2018 10:29 am
- Forum: News, Suggestions, and FAQ
- Topic: Errors/Warnings/Bugs
- Replies:
**524** - Views:
**102913**

### Re: Errors/Warnings/Bugs

For me the problem appears in Chrome but not in IE...

- Tue Nov 27, 2018 4:42 am
- Forum: News, Suggestions, and FAQ
- Topic: Errors/Warnings/Bugs
- Replies:
**524** - Views:
**102913**

### Re: Errors/Warnings/Bugs

Now I have this problem...

If I try to view my posts from 173-180, then am directed to the sign-in page even though am not signed-out of PE.

If I try to view my posts from 173-180, then am directed to the sign-in page even though am not signed-out of PE.

- Fri Aug 24, 2018 4:14 am
- Forum: Programming languages
- Topic: which compiler to use for c++ programs
- Replies:
**2** - Views:
**4556**

### Re: which compiler to use for c++ programs

Like v6ph1 said, if you are looking for online compilers, repl is my favourite..

- Fri Aug 10, 2018 5:52 am
- Forum: Number Theory
- Topic: An Infinite Prime Number Generator
- Replies:
**5** - Views:
**5611**

### Re: An Infinite Prime Number Generator

I changed the code to remove the loop-checking and use modified-step values but still no improvements in timing. For example, the mod-2 version takes ~ 75 secs to list all primes upto 10^8, the mod-6 version takes ~ 85 secs whereas the step-adjusted-mod-6 version takes ~ 95 secs. step-adjusted-mod-6...

- Thu Aug 09, 2018 12:00 pm
- Forum: Number Theory
- Topic: An Infinite Prime Number Generator
- Replies:
**5** - Views:
**5611**

### Re: An Infinite Prime Number Generator

Thanks v6ph1. I too arrived at the same loop for making the program slow. But I think it may be slightly different. Rather than the loop checking, I think the runs more often as the chance of hitting the numbers with mod in the given set becomes low. That I think is the trade-off in the higher mod v...

- Thu Aug 09, 2018 3:51 am
- Forum: Number Theory
- Topic: An Infinite Prime Number Generator
- Replies:
**5** - Views:
**5611**

### An Infinite Prime Number Generator

Hi all, I recently saw a post on an Infinite Prime Number Generator on Stack Exchange given below. from itertools import count from timeit import default_timer start = default_timer() # ideone.com/aVndFM def postponed_sieve(): # postponed sieve, by Will Ness for c in (2, 3, 5, 7): # original code Da...

- Tue Jul 10, 2018 1:59 pm
- Forum: Number
- Topic: an old maths olympiad question
- Replies:
**28** - Views:
**15586**

### Re: an old maths olympiad question

@ jaap , I think you did all the heavy lifting leaving just the algebra to me. The key to solving this problem is to pick the 'central angle' as the variable of interest. Though the 'cubic' approach ended nowhere, it reminded me of the trick of evaluating $\sin(\pi/5)$ exactly, which I kinda used to...

- Tue Jul 10, 2018 11:13 am
- Forum: Number
- Topic: an old maths olympiad question
- Replies:
**28** - Views:
**15586**

### Re: an old maths olympiad question

... It is straightforward to see that: A1A2 = 2sin(x) A1A3 = 2sin(2x) A1A4 = 2sin(3x) From here, we have, $\displaystyle\frac{1}{\sin x}=\frac{1}{\sin 2x}+\frac{1}{\sin 3x}$ $\displaystyle\sin 2x=\frac{\sin x \sin 3x}{\sin 3x-\sin x}=\frac{\sin x \sin 3x}{2\sin x-4 \sin^3 x}=\frac{\sin x\sin 3x}{2 ...

- Tue Jun 12, 2018 11:00 am
- Forum: Combinatorics
- Topic: Die and matchsticks game from 'The Goal'
- Replies:
**0** - Views:
**8346**

### Die and matchsticks game from 'The Goal'

Hi All, This post is about an analysis of a game described in Goldratt's best seller 'The Goal'. The game is as follows: Consider $b$ bins of infinite capacity in a row with an imaginary Source of infinite matchsticks. Matchsticks are transferred to the bins in the following manner: For every bin, m...

- Mon Apr 30, 2018 5:49 pm
- Forum: Clarifications on Project Euler Problems
- Topic: Problem 549
- Replies:
**19** - Views:
**5063**

### Re: Problem 549

We are not supposed to post partial answers in this forum. But anyway, the value you posted seems to be wrong. Happy solving!!merlinnimue wrote: ↑Mon Apr 30, 2018 5:08 pmQuick sanity check: can anyone confirm if S(10^6) =xxxxxxxxxxxxxxx?

- Mon Apr 09, 2018 8:00 am
- Forum: News, Suggestions, and FAQ
- Topic: New Awards (10 April 2015)
- Replies:
**9** - Views:
**3132**

### Re: New Awards (10 April 2015)

A suggestion on awards.. Is there a possibility of introducing country-wise awards.. Something like 'First in your country', 'Top solver of your country' and something like that?? The Elite group is highly competitive to even make an attempt at getting some awards like 'The Gold Medal'. Would probab...

- Tue Mar 27, 2018 7:04 am
- Forum: Clarifications on Project Euler Problems
- Topic: Problem 623
- Replies:
**17** - Views:
**2754**

### Re: Problem 623

Thank you all.. Solved it... For someone who didn't study computer science, the whole problem seemed very convoluted but fortunately the structure of the problem was quite simple.. One more thing.. Should the number of solvers be hidden until we solve a problem? At least recently for me, I'm taking ...

- Mon Mar 26, 2018 5:48 am
- Forum: Clarifications on Project Euler Problems
- Topic: Problem 623
- Replies:
**17** - Views:
**2754**

### 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 s...