Re^3: Travelling problem (Anyone better 86850?)

Replies are listed 'Best First'.
Re^4: Travelling problem (Anyone better 86850?) by BrowserUk (Patriarch) on Dec 23, 2013 at 16:04 UTC
I have the impression that a little branch and bound with just the 3 or 4 shortest edges per node (instead of just one) would quickly produce much better results. Prove it! (You've done a great job of quoting wikipedia; how about putting some of your reading into practice?) With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply]
Re^5: Travelling problem (Anyone better 86850?) by hdb (Monsignor) on Dec 23, 2013 at 18:09 UTC
Branch & Bound with the two shortest edges finds the following in less than 30 seconds: `95166 90498 90298 89653 88925 88838 86867 85294 84860` [download]	[reply] [d/l]
Re^6: Travelling problem (Anyone better 86850?) by BrowserUk (Patriarch) on Dec 23, 2013 at 18:51 UTC
There's thems that talk, and thems that do :) With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply]
Re^7: Travelling problem (Anyone better 86850?) by hdb (Monsignor) on Dec 23, 2013 at 19:39 UTC
Re^8: Travelling problem (Anyone better 86850?) by BrowserUk (Patriarch) on Dec 24, 2013 at 03:24 UTC
Some notes below your chosen depth have not been shown here
Re^7: Travelling problem (Anyone better 86850?) by LanX (Saint) on Dec 23, 2013 at 19:04 UTC
Re^8: Travelling problem (Anyone better 86850?) by BrowserUk (Patriarch) on Dec 23, 2013 at 20:09 UTC
Re^5: Travelling problem (Anyone better 86850?) by LanX (Saint) on Dec 23, 2013 at 16:47 UTC
And what have you "proven" so far except dropping numbers and (most probably) miscalculating the lower bound? Cheers Rolf ( addicted to the Perl Programming Language)	[reply]
Re^6: Travelling problem (Anyone better 86850?) by BrowserUk (Patriarch) on Dec 23, 2013 at 17:17 UTC
except dropping numbers Check it yourself: `86850 [ 0 5 13 22 8 3 12 20 16 11 6 1 10 15 7 18 2 19 17 14 4 9 21 23 +]` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]
Re^6: Travelling problem (Anyone better 86850?) by tangent (Parson) on Dec 23, 2013 at 17:43 UTC
Or even: `85923 [1,2,11,16,7,8,12,17,21,6,13,4,9,23,14,10,22,15,5,18,20,3,19,24]` [download]	[reply] [d/l]
Re^4: Travelling problem (Anyone better 86850?) by hdb (Monsignor) on Dec 23, 2013 at 16:58 UTC
My branch and bound is running on the three shortest nodes for 27hrs now. Best so far 88491.	[reply]
Re^5: Travelling problem (Anyone better 86850?) by LanX (Saint) on Dec 23, 2013 at 17:09 UTC
Well, which is far better than 95166. =) Anyway both results are already within 20% from the optimum. May I ask, if you cache intermediate results? If you go from 1 to 24 and reach node X again via the same nodes (just other order) then the options for the rest of the way are identical. In my experience such memoizing helps to bound very efficiently. update This caching is maybe better applied in a "breadth first search" to reduce pathes. Cheers Rolf ( addicted to the Perl Programming Language)	[reply]
Re^6: Travelling problem (Anyone better 86850?) by hdb (Monsignor) on Dec 23, 2013 at 18:22 UTC
No caching, just brute force. I have now cleaned my code, you have to give the bound on the command line: Read more... (8 kB)	[reply] [d/l]
Re^7: Travelling problem (Anyone better 86850?) by LanX (Saint) on Dec 23, 2013 at 18:30 UTC


Do you know where your variables are?
	PerlMonks

Re^3: Travelling problem (Anyone better 86850?)

update