Add the incremental evaluation function of the UBQP problem

git-svn-id: svn://scm.gforge.inria.fr/svnroot/paradiseo@1941 331e1502-861f-0410-8da2-ba01fb791d7f

trunk/paradiseo-mo/src/problems/eval/moUBQPSimpleIncrEval.h

@@ -0,0 +1,90 @@
+/*
+<moUBQPSimpleIncrEval.h>
+Copyright (C) DOLPHIN Project-Team, INRIA Lille - Nord Europe, 2006-2010
+
+Sebastien Verel, Arnaud Liefooghe, Jeremie Humeau
+
+This software is governed by the CeCILL license under French law and
+abiding by the rules of distribution of free software.  You can  ue,
+modify and/ or redistribute the software under the terms of the CeCILL
+license as circulated by CEA, CNRS and INRIA at the following URL
+"http://www.cecill.info".
+
+In this respect, the user's attention is drawn to the risks associated
+with loading,  using,  modifying and/or developing or reproducing the
+software by the user in light of its specific status of free software,
+that may mean  that it is complicated to manipulate,  and  that  also
+therefore means  that it is reserved for developers  and  experienced
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+encouraged to load and test the software's suitability as regards their
+requirements in conditions enabling the security of their systems and/or
+data to be ensured and,  more generally, to use and operate it in the
+same conditions as regards security.
+The fact that you are presently reading this means that you have had
+knowledge of the CeCILL license and that you accept its terms.
+
+ParadisEO WebSite : http://paradiseo.gforge.inria.fr
+Contact: paradiseo-help@lists.gforge.inria.fr
+*/
+
+#ifndef _moUBQPSimpleIncrEval_H
+#define _moUBQPSimpleIncrEval_H
+
+#include <eval/moEval.h>
+#include <eval/UbqpEval.h>
+
+/**
+ * Incremental evaluation Function for the UBQPSimple problem
+ */
+template< class Neighbor >
+class moUBQPSimpleIncrEval : public moEval<Neighbor>
+{
+public:
+  typedef typename Neighbor::EOT EOT;
+  
+  /*
+   * default constructor
+   * @param _ubqpEval full evaluation of the UBQP problem
+   */
+  moUBQPSimpleIncrEval(UbqpEval<EOT> & _ubqpEval) {
+    n = _ubqpEval.getNbVar();
+    Q = _ubqpEval.getQ();
+  }
+
+  /*
+   * Incremental evaluation of the neighbor for the UBQP problem (linear time complexity)
+   * @param _solution the solution to move (bit string)
+   * @param _neighbor the neighbor to consider (of type moBitNeighbor)
+   */
+  virtual void operator()(EOT & _solution, Neighbor & _neighbor) {
+    unsigned int i = _neighbor.index();
+    unsigned int j;
+
+    int d = Q[i][i]; 
+
+    for(j = 0; j < i; j++)
+      if (_solution[j] == 1)
+	d += Q[i][j];
+
+    for(j = i+1; j < n; j++)
+      if (_solution[j] == 1)
+	d += Q[j][i];
+
+    if (_solution[i] == 0)
+      _neighbor.fitness(_solution.fitness() + d);
+    else
+      _neighbor.fitness(_solution.fitness() - d);
+
+  }
+
+private:
+  // number of variables
+  int n;
+  
+  // matrix Q (supposed to be in lower triangular form)
+  int ** Q;
+    
+};
+
+#endif
+