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Use of callbacks to output the search tree Description Use of callbacks to output the search tree; same problem
as in 'disjunctive.mos'.
Source Files By clicking on a file name, a preview is opened at the bottom of this page.
solution.mos (!**************************************************************** CP example problems =================== file solution.mos ````````````````` Using callbacks to output the search tree. (c) 2008 Artelys S.A. and Fair Isaac Corporation Creation: 2005, rev. Apr. 2022 *****************************************************************!) model "Using callbacks" uses "kalis" declarations NBTASKS = 5 TASKS = 1..NBTASKS ! Set of tasks DUR: array(TASKS) of integer ! Task durations DURs: array(set of cpvar) of integer ! Durations DUE: array(TASKS) of integer ! Due dates WEIGHT: array(TASKS) of integer ! Weights of tasks start: array(TASKS) of cpvar ! Start times tmp: array(TASKS) of cpvar ! Aux. variable tardiness: array(TASKS) of cpvar ! Tardiness twt: cpvar ! Objective variable zeroVar: cpvar ! 0-valued variable Strategy: array(range) of cpbranching ! Branching strategy Disj: set of cpctr ! Disjunctions nodesx: array(range) of integer ! x-coordinates nodesy: array(range) of integer ! y-coordinates currentpos: integer end-declarations ! Initialization of search tree data nodesx(0) := 1 nodesy(0) := 0 currentpos := 1 ! ********************************************************** ! solution_found: called each time a solution is found ! ********************************************************** procedure solution_found writeln("A solution has been found :") forall (t in TASKS) writeln("[", getsol(start(t)), "==>", (getsol(start(t)) + DUR(t)), "]:\t ", getsol(tardiness(t)), " (", getsol(tmp(t)), ")") writeln("Total weighted tardiness: ", getsol(twt)) end-procedure ! ********************************************************** ! node_explored: called each time a node is explored ! ********************************************************** procedure node_explored nodesx(currentpos) += 1 if nodesx(currentpos-1)>nodesx(currentpos) then nodesx(currentpos) := nodesx(currentpos-1) end-if nodesy(currentpos) := -currentpos writeln("[Node explored depth : " , (-nodesy(currentpos)), "]") end-procedure ! ********************************************************** ! go_down_branch: called each time the search goes down ! a branch of the search tree ! ********************************************************** procedure go_down_branch writeln("[Branch go_down " , (-nodesy(currentpos)) , "]") currentpos := currentpos + 1 end-procedure ! ********************************************************** ! go_up_branch: called each time the search goes up ! a branch of the search tree ! ********************************************************** procedure go_up_branch currentpos := currentpos - 1 writeln("[Branch go_up " , (-nodesy(currentpos)) , "]") end-procedure ! ********************************************************** ! Problem definition ! ********************************************************** DUR :: [21,53,95,55,34] DUE :: [66,101,232,125,150] WEIGHT :: [1,1,1,1,1] setname(twt, "Total weighted tardiness") zeroVar = 0 setname(zeroVar, "zeroVar") ! Setting up the decision variables forall (t in TASKS) do start(t) >= 0 setname(start(t), "Start("+t+")") DURs(start(t)):= DUR(t) tmp(t) = start(t) + DUR(t) - DUE(t) setname(tardiness(t), "Tard("+t+")") tardiness(t) = maximum({tmp(t), zeroVar}) end-do twt = sum(t in TASKS) (WEIGHT(t) * tardiness(t)) ! Create the disjunctive constraints disjunctive(union(t in TASKS) {start(t)}, DURs, Disj, 1) ! The setxxxcallback methods must be called before ! setting the branching with 'cp_set_branching' cp_set_solution_callback(->solution_found) cp_set_node_callback(->node_explored) cp_set_branch_callback(->go_down_branch, ->go_up_branch) Strategy(0):= settle_disjunction Strategy(1):= split_domain(KALIS_MAX_DEGREE,KALIS_MIN_TO_MAX) cp_set_branching(Strategy) if not cp_minimize(twt) then writeln("problem is inconsistent") exit(0) end-if end-model | |||||||||||||||
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