Problem 353

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BostonBear
Posts: 17
Joined: Thu Apr 28, 2011 3:48 am
Location: Saugus, MA

Problem 353

I am a little confused about the new problem. This sphere has integer coordinates. Yet we are not given a specific size, so as far as I can tell , for a generic r, there are only 6 integer coordinates. (r,0,0), (0,r,0), (0,0,r) and its antipodals. Is there something I'm missing here? Does each trip to a station have to be a direct trip, or can you change directions before you get to the next station?

Edit, never mind, I figured out what I was not seeing right
Last edited by BostonBear on Sun Oct 09, 2011 4:36 am, edited 1 time in total.

TripleM
Posts: 382
Joined: Fri Sep 12, 2008 2:31 am

Re: Euler Problem 353

You are given a specific size - r is equal to 2^n - 1 for each value of n from 1 to 15.

cyrillic
Posts: 1
Joined: Wed Oct 12, 2011 10:25 am

Euler Problem 353

Could I check with someone the value of M(r) for n=15 I'm getting, to validate my code? Cheers.

thundre
Posts: 356
Joined: Sun Mar 27, 2011 9:01 am

Re: Euler Problem 353

cyrillic wrote:Could I check with someone the value of M(r) for n=15 I'm getting, to validate my code? Cheers.
PM it to me and I'll tell you whether it matches mine.

Arthelais
Posts: 3
Joined: Wed Oct 08, 2014 1:57 pm

Re: Problem 353

Could someone verify for me whether M(1000) is equal to 0.05174553024? I feel like I am facing a rounding error and I can't seem to figure it out.

MuthuVeerappanR
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Re: Problem 353

Is this problem prone to precision errors?? I tried a couple of methods and they all provide the same for value upto M(10). But somehow my answer is not getting accepted.

It is not knowledge, but the act of learning, not possession but the act of getting there, which grants the greatest enjoyment.

sjhillier
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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.

MuthuVeerappanR
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Re: Problem 353

Thanks sjhillier. I solved it yesterday. Turns out one of my assumptions only fails for the k = 8 case.

It is not knowledge, but the act of learning, not possession but the act of getting there, which grants the greatest enjoyment.

sjhillier
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Re: Problem 353

MuthuVeerappanR wrote:
Thu Jun 08, 2017 1:34 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.

bleh0.5
Posts: 1
Joined: Tue Aug 14, 2018 4:54 pm

Re: Problem 353

Are we supposed to calculate every single integer set of coordinates or are the only coordinates going to be (0,r,r) and stuff like that

RobertStanforth
The admissible paths (from which you are asked to find the one with the lowest risk) are permitted to use any of the integer-coordinate points on the surface of $C$. The problem statement does not confine you to a special subset of them.