Comments on: ACM SPPC (And related excitement) http://chris.neugebauer.id.au/2009/09/13/acm-sppc-and-related-excitement/ Indeed it is. Tue, 10 Jan 2012 23:48:27 +0000 hourly 1 http://wordpress.org/?v=3.0.4 By: Chris Neugebauer http://chris.neugebauer.id.au/2009/09/13/acm-sppc-and-related-excitement/#comment-747 Chris Neugebauer Sun, 13 Sep 2009 22:14:25 +0000 http://chris.neugebauer.id.au/2009/09/13/acm-sppc-and-related-excitement/#comment-747 Hi Kevin,<br /> <br /> Yes, standard BFS was fast enough for I -- the maximal state space for a 1000x1000 grid over 4 orientations is 4x10^6, which we were able to search out in ~2 seconds (by terminating on first discovery, and only putting new states into the queue, something you can do with BFS and not Dijkstra's).<br /> <br /> H was being worked on by Simon, using a standard solution to the Stable Marriages Problem; he did something that took O(N^3) time in there, and hence TLEd. Hi Kevin,

Yes, standard BFS was fast enough for I — the maximal state space for a 1000×1000 grid over 4 orientations is 4×10^6, which we were able to search out in ~2 seconds (by terminating on first discovery, and only putting new states into the queue, something you can do with BFS and not Dijkstra’s).

H was being worked on by Simon, using a standard solution to the Stable Marriages Problem; he did something that took O(N^3) time in there, and hence TLEd.

]]> By: Kevin http://chris.neugebauer.id.au/2009/09/13/acm-sppc-and-related-excitement/#comment-746 Kevin Sun, 13 Sep 2009 08:33:54 +0000 http://chris.neugebauer.id.au/2009/09/13/acm-sppc-and-related-excitement/#comment-746 Thanks for posting your analysis.  I competed in UQ::TripleLinkedList as the coder.  For Problem I, was a plain ol' BFS fast enough?  Our team went straight to the A* algorithm because we thought a BFS would be too slow for it.<br /> <br /> I'd be interested to know what your algorithm for H was, if you had that ready. Thanks for posting your analysis.  I competed in UQ::TripleLinkedList as the coder.  For Problem I, was a plain ol’ BFS fast enough?  Our team went straight to the A* algorithm because we thought a BFS would be too slow for it.

I’d be interested to know what your algorithm for H was, if you had that ready.

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