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S Jul 31, 2014 at 15:05 history bounty ended CommunityBot
S Jul 31, 2014 at 15:05 history notice removed CommunityBot
Jul 29, 2014 at 14:17 history edited joro CC BY-SA 3.0
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S Jul 23, 2014 at 13:45 history bounty started joro
S Jul 23, 2014 at 13:45 history notice added joro Draw attention
Jul 23, 2014 at 13:40 history edited joro CC BY-SA 3.0
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Jul 22, 2014 at 11:52 comment added joro @Jernej I don't think the deletion will work. It terminates in trees, not in cliques. Trees are 2-colorable and don't see how to terminate early. Do you see such way?
Jul 22, 2014 at 11:43 comment added Jernej @Joro. Question - given that you work with 4-regular graphs, isn't it faster to use the edge deleting recursion? I am not sure you can say anything about the time complexity from the execution on instances of a concrete size since run time may as well be a function that "behaves" as a polynomial up to a certain fixed threshold .
Jul 22, 2014 at 11:41 comment added joro @Jernej I mean the number of calls in the recursion appear polynomial to me. Exponential in 300 will take long. Exponential in 4-regular 4-chromatic order 75 too, though in practice this is fast. Did you notice the link to sage code?
Jul 22, 2014 at 11:33 comment added joro @Jernej Thanks. I don't want isomorphism. The current sage implementation does 300 vertices 4 regular in about minute. Appears to me hardest are 4-chromatic, though they seem polynomial to me too.
Jul 22, 2014 at 11:28 comment added Jernej @Joro, Btw, a way to speed up such recursion is to cache graphs, see how this is done for the chromatic polynomial to gain an extreme speedup trac.sagemath.org/ticket/14529 Though this introduces the isomorphism problem and breaks complexity analysis.
Jul 22, 2014 at 10:55 comment added joro @Jernej What is the fastest way say in Boost to find induced diamonds (K_4 minus edge)?
Jul 22, 2014 at 10:30 comment added Jernej Errr, I missed that one sorry.
Jul 21, 2014 at 11:59 comment added Emil Jeřábek Recursion to instances smaller by an additive constant is the standard technique for beating the obvious brute-force search algorithm for a wide variety of NP-hard problems. It normally leads to runtimes of the form $c^n$. Are you familiar with state-of-the-art 3-colouring algorithms such as sciencedirect.com/science/article/pii/S0020019010003595 , ics.uci.edu/~eppstein/pubs/Epp-SODA-01.pdf ?
Jul 21, 2014 at 11:49 comment added joro Very related question on cstheory: cstheory.stackexchange.com/questions/25299/…
Jul 21, 2014 at 10:36 history asked joro CC BY-SA 3.0