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May 23, 2017 at 12:37 history edited CommunityBot
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May 28, 2013 at 5:17 answer added Urakov timeline score: 2
Feb 11, 2013 at 14:15 answer added Andrea Marino timeline score: 5
Apr 17, 2011 at 13:09 answer added trg787 timeline score: -2
Dec 6, 2010 at 21:04 comment added Lucas K. I just wonder. If the graph is a tree, then there is a simple trick. Just, start with a point, find the point furthest away. Then search the point furthest away from that point. Then you have the longest path (or one of them, in case of multiple solutions). Suppose you apply the same method on a graph, instead of tree. The points on the paths already found, can not be the end points of such longest path. So, you skip them as potential candidates. You repeat this, until all points have been tried. Could this work?
Dec 6, 2010 at 20:18 vote accept aorq
Dec 6, 2010 at 20:03 answer added David Eppstein timeline score: 9
Jan 13, 2010 at 1:45 comment added Ryan Williams Do you need the exact diameter, or would approximate methods suffice? (I have the suspicion that an exact "truly subcubic" diameter finding algorithm would yield a subcubic all-pairs shortest paths algorithm on unweighted graphs. But note, the latter can be theoretically solved in matrix multiplication time...)
Jan 12, 2010 at 1:43 answer added Wilson timeline score: 1
Jan 11, 2010 at 17:17 comment added aorq @Steve: Thanks for the reference. Their "matrix methods" section essentially runs the Bellman–Ford algorithm in time O(V^3). Their "non-matrix methods" sections runs Dijktra for each vertex, which is Johnson's algorithm at O(V^2 log V + VE). However, they combine this with an upper bound for the diameter, obtained from the diameter of the minimum spanning tree (which can be computed quite efficiently). Unfortunately, if their bound is not met (and they have no reason to believe it will be), their suggestion is simply Johnson's algorithm for all-pairs shortest paths.
Jan 11, 2010 at 16:49 answer added Mariano Suárez-Álvarez timeline score: 1
Jan 11, 2010 at 16:49 comment added Steve Huntsman See the "non-matrix methods" section of sawww.epfl.ch/SIC/SA/publications/SCR98/scr10-page3.html
Jan 11, 2010 at 16:36 history asked aorq CC BY-SA 2.5