bande: Solutions.cc 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  * Implementation of class bande::Solutions.
00025  */
00026 
00027 #include "bande.hh"
00028 
00029 namespace bande {
00030 
00031   /**
00032    * Write all future solutions to the specified file.
00033    * @param file the file to which solutions will be written.
00034    */
00035   void Solutions::writeToFile(const char* file) {
00036     clearOut();
00037     out = new std::ofstream(file);
00038     ownOut = true;
00039   }
00040 
00041   /**
00042    * Write all future solutions to the specified stream.
00043    * The stream will nod be closed at the end.
00044    * @param outStream the stream to which solutions will be written.
00045    */
00046   void Solutions::writeToStream(std::ostream& outStream) {
00047     clearOut();
00048     out = &outStream;
00049     ownOut = false;
00050   }
00051 
00052   /**
00053    * Ensure proper cleanup.
00054    * This deletes the output stream if this object created it in the
00055    * first place.
00056    */
00057   void Solutions::clearOut() {
00058     if (ownOut) {
00059       delete out;
00060       out = 0;
00061       ownOut = false;
00062     }
00063   }
00064 
00065   /**
00066    * Method invoked for every solution found.
00067    * Right now it only writes the solution, but a future version might
00068    * store the solution for postprocessing or something like this.
00069    *
00070    * @param ip the integer program in the starte representing the
00071    *           current solution.
00072    */
00073   void Solutions::solution(const IntegerProgram& ip) {
00074     writeSolution(ip);
00075   }
00076 
00077   /**
00078    * Write solution to output stream.
00079    *
00080    * The solution is written as a single line, with columns separated
00081    * by tabs. Each column gives the name of one problem variable, an
00082    * equals sign, and the value of that variable in the current
00083    * solution. Variables with a value of zero are omitted.
00084    *
00085    * @param ip the integer program in the starte representing the
00086    *           current solution.
00087    */
00088   void Solutions::writeSolution(const IntegerProgram& ip) {
00089     if (!out) return;
00090     const char* delim = "";
00091     for (int col = 0; col < ip.getNumCols(); ++col) {
00092       int val = ip.getIntSolution(col);
00093       if (!val) continue;
00094       *out << delim << ip.getColName(col) << "=" << val;
00095       delim = "\t";
00096     }
00097     *out << std::endl;
00098   }
00099 
00100 }