Search found 15 matches

by jimfan
Thu Jan 17, 2019 2:54 pm
Forum: Clarifications on Project Euler Problems
Topic: Problem 106
Replies: 32
Views: 8898

Re: Problem 106

I cannot explain why... This question appears to be a riddle more than a mathematics / programming challenge...
by jimfan
Thu Jan 17, 2019 2:45 pm
Forum: Recreational
Topic: Winning Lottery with Prime Number!?
Replies: 8
Views: 3086

Re: Winning Lottery with Prime Number!?

Possibly be "The Call of the Primes: Surprising Patterns, Peculiar Puzzles, and Other Marvels of Mathematics", by Owen O'Shea, publisher Prometheus Books. If I am correct both are from British.
by jimfan
Sun Jan 21, 2018 9:03 am
Forum: Recreational
Topic: Winning Lottery with Prime Number!?
Replies: 8
Views: 3086

Re: Winning Lottery with Prime Number!?

Hello Stephen, Thank you for sharing your presentation. It seems that "birthday numbers are more popular" applies to the West too. Unluckily I could not recall the book correctly. At first I thought the book was "What Are the Odds?" by Tim Glynne-Jones, published by Arcturus Publishing Limited (ISBN...
by jimfan
Sat Jan 13, 2018 12:26 pm
Forum: Recreational
Topic: Winning Lottery with Prime Number!?
Replies: 8
Views: 3086

Re: Winning Lottery with Prime Number!?

Hi jaap, Thanks for demonstrating the probability! Only the idea of "betting prime numbers" didn't pop up in my mind at all before, together with the 6/7 prime, the coincidence adds a little mistique... At least from my oriental perspective 8-) I am betting on Fibonacci numbers in coming draw, which...
by jimfan
Fri Jan 12, 2018 3:28 pm
Forum: Recreational
Topic: Winning Lottery with Prime Number!?
Replies: 8
Views: 3086

Winning Lottery with Prime Number!?

Yesterday night we had a lottery snow ball more than HKD 110 million. Suddenly an idea floated up: Will betting all prime numbers get me first prize? The draw picks 6 plus 1 special number out of 1 to 49. A gambler bets for 6 out of 1 to 49. If gambler hit all 6 non-special number, he gets first pri...
by jimfan
Fri Jan 12, 2018 3:09 pm
Forum: Programming languages
Topic: New Preferred Programming Language Requests
Replies: 151
Views: 45837

Re: New Preferred Programming Language Requests

euler wrote:
Fri Dec 22, 2017 12:47 pm
If you were only allowed to solve every problem with one language, then which one, in your opinion, would it be?
It would still be APL, specifically, NARS2000, the ultimate desktop calculator. Mr. Bob Smith told in comp.lang.apl that he added high precision number for tackling Project Euler!
by jimfan
Sun Dec 24, 2017 12:57 pm
Forum: Number
Topic: Repeating Decimal and Prime Number
Replies: 5
Views: 2557

Re: Repeating Decimal and Prime Number

Hello jaap, Thank you for the great reminder: Long division! With input from you and v6ph1, plus two more hours of pencil and paper calculation, I finally get it. This is how I can reason about the phenomenon: 1. Let's visualise 10^N in form of 10^N = P * Quotient + Reminder. Consider P = 7 which is...
by jimfan
Fri Dec 15, 2017 4:59 pm
Forum: Number
Topic: Repeating Decimal and Prime Number
Replies: 5
Views: 2557

Re: Repeating Decimal and Prime Number

It's a directly follows fermat's little theorem: 10^(p-1) == 1 (mod p) I feel embarrassed to admit: I could not see / understand why 10^(p-1) == 1 (mod p) is the reason, even after reading about introductory number theory in these day. I encounterd some congruences such as "Wilson's theorem" but ye...
by jimfan
Tue Dec 12, 2017 10:03 am
Forum: Programming languages
Topic: New Preferred Programming Language Requests
Replies: 151
Views: 45837

Re: New Preferred Programming Language Requests

Hello all, Quite a discussion. As time goes by I find that choosing one language category (my choice: APL/J/K) cannot accurately describe the tool set I use. As example, I just solved and re-solved problem 093 (arithmatic expression), using a basket of language / tool in pipeline. Here's how: 1. Pro...
by jimfan
Tue Dec 12, 2017 9:39 am
Forum: Resources
Topic: ProjectEuler in Persian
Replies: 2
Views: 2662

Re: ProjectEuler in Persian

I wish I can do Persian too!
by jimfan
Fri Dec 08, 2017 12:15 pm
Forum: News, Suggestions, and FAQ
Topic: In Response to Problem Thread of 076
Replies: 6
Views: 1015

Re: In Response to Problem Thread of 076

Hello hk,

I concur and to demonstrate my determination, my github repo for PE solution has been removed.

Surely I do encourage other contenders to do the same.

Thanks for your advice and now it's time for me to stop mumbling and move on and enjoy the math and coding again.

Jim
by jimfan
Wed Dec 06, 2017 9:41 am
Forum: News, Suggestions, and FAQ
Topic: In Response to Problem Thread of 076
Replies: 6
Views: 1015

Re: In Response to Problem Thread of 076

Hello traxex, euler, Thank you for your kind response and encouragement. Might be I have been taking other people's dishonesty too seriously - after all it is not me losing a chance for learning new math skill. To math mortals like me, generating function is truly a genius way to solve partition cou...
by jimfan
Tue Dec 05, 2017 6:45 pm
Forum: News, Suggestions, and FAQ
Topic: In Response to Problem Thread of 076
Replies: 6
Views: 1015

In Response to Problem Thread of 076

Dear all, I cannot stop myself sharing with you my post in the question thread. It appears people's moral has changed quite a lot in 2017: <begin> Does someone really regard himself having the problem solved by looking at partition(100) in Wikipaedia and then subtract one from it????? I can safely g...
by jimfan
Sat Oct 14, 2017 5:44 pm
Forum: Programming languages
Topic: APL
Replies: 3
Views: 3456

Re: APL

Hi,

I come a few years late... Just solved 070 using NARS2000 and sometimes Dyalog APL.

At first I only wanted to learn APL via PE questions. Now it is the mathematics that keeps me going.

Jim
by jimfan
Fri Sep 29, 2017 3:22 pm
Forum: Number
Topic: Repeating Decimal and Prime Number
Replies: 5
Views: 2557

Repeating Decimal and Prime Number

Hi, Just solved problem 026 which was the only obstacle to my flawless-fifty. I know this has been dimly mentioned in problem clarification section, but I can't suppress the excitement of discovering this: For some prime number P below 1000, 1/P gives repeating decimal where the length of repeating ...