Hi Zoe,
I just fixed the bug in the trunk: now no-goods are extracted properly even for solutions. The problem was that the last leaf was missing in a no-good for a solution and in order to get that one, the search engines needed to be changed so that when they are stopped in for a restart, the path used for no-good extraction will really point to the next node in the tree... Expect a release pretty soon Best Christian -- Christian Schulte, Professor of Computer Science, KTH, www.gecode.org/~schulte/ From: ziche...@gmail.com [mailto:ziche...@gmail.com] On Behalf Of Zhu Zichen's cse Sent: Tuesday, December 16, 2014 4:14 PM To: cschu...@kth.se Cc: users@gecode.org Subject: Re: [gecode-users] A problem for restart Dear Christian, Here are the codes. Many thanks. Zichen On Tue, Dec 16, 2014 at 11:04 PM, Christian Schulte <cschu...@kth.se> wrote: Hi Zichen, MPG does not make a promise here: it says "the solution might not be found again" but it does not give you a guarantee. But for your example I would have to know how nqueen_rbs looks like. Cheers Christian -- Christian Schulte, Professor of Computer Science, KTH, www.gecode.org/~schulte/ From: users-boun...@gecode.org [mailto:users-boun...@gecode.org] On Behalf Of Zhu Zichen's cse Sent: Tuesday, December 16, 2014 3:43 PM To: users@gecode.org Subject: [gecode-users] A problem for restart Dear all, I met a problem when using ​restart in Gecode. I simply use restart to find all solutions for 4-Queens while use the same heuristic after each restart: ./nqueen_rbs -restart geometric -restart-scale 2 -restart-base 10 -nogoods 1 -nogoods-limit 128 4 But I got into an infinite loop which keeps printing the first solution. According to the newest version of document "MPG" (page 160), the master() function posts no-goods when the a solution is found. This means the same solution will not be found again. I rewrite the master() function by changing the last line "return true" into "return false", now all solutions are generated without trapped into a loop. I am wondering why the infinite loop happens and whether Gecode has truly recorded previous solutions as nogoods as the document says. Thanks for help. Zichen Image removed by sender.
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