bande: BranchControl.hh Source File

00001 /*
00002  *  Copyright 2007 Martin von Gagern
00003  *
00004  *
00005  *  This file is part of bande.
00006  *
00007  *  bande is free software; you can redistribute it and/or modify
00008  *  it under the terms of the GNU General Public License as published by
00009  *  the Free Software Foundation; either version 3 of the License, or
00010  *  (at your option) any later version.
00011  *
00012  *  bande is distributed in the hope that it will be useful,
00013  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  *  GNU General Public License for more details.
00016  *
00017  *  You should have received a copy of the GNU General Public License
00018  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
00019  */
00020 
00021 
00022 /**
00023  * @file
00024  * Interface of class bande::BranchControl.
00025  */
00026 
00027 namespace bande {
00028 
00029   /**
00030    * Central control of branching algorithm
00031    *
00032    * This class coordinates the search for solutions. It is probably
00033    * the most interesting class of the whole project.
00034    */
00035   class BranchControl {
00036   public:
00037 
00038     /**
00039      * Constructor.
00040      *
00041      * @param sols the object where solutions will be collected.
00042      */
00043     BranchControl(Solutions& sols) : sols(sols) { }
00044 
00045     /**
00046      * Destructor.
00047      */
00048     virtual ~BranchControl() { }
00049 
00050     /**
00051      * Public access to private ip member.
00052      */
00053     IntegerProgram& getIP() { return ip; }
00054 
00055     void run();
00056 
00057   private:
00058 
00059     /**
00060      * Current integer program.
00061      *
00062      * Initially this corresponds to the input program, but as the
00063      * algorithm proceeds, tighter bounds will be placed on the
00064      * variables, to reflect branching decisions.
00065      *
00066      * The ip is part of BranchControl, not initialized as a separate
00067      * object in Settings::run(), in order to avoid one pointer
00068      * indirection when accessing this object. It can still be
00069      * accessed fully through getIP().
00070      */
00071     IntegerProgram ip;
00072 
00073     /**
00074      * Keep track of changes, used for switching between branches.
00075      */
00076     UndoManager um;
00077 
00078     /**
00079      * Record solutions.
00080      */
00081     Solutions& sols;
00082 
00083     /**
00084      * Collect some statistical informations.
00085      */
00086     Statistics statistics;
00087 
00088     void branch(int depth);
00089     int branchCol();
00090   };
00091 
00092 }