incremental evaluation for one max when flips several bits

mo/src/problems/eval/moOneMaxBitsIncrEval.h

@@ -0,0 +1,64 @@
+/*
+<moOneMaxIncrEval.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
+professionals having in-depth computer knowledge. Users are therefore
+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 _moOneMaxBitsIncrEval_H
+#define _moOneMaxBitsIncrEval_H
+
+#include <eval/moEval.h>
+
+/**
+ * Incremental evaluation Function for the OneMax problem
+ * when k bits are flipped (moBitsNeighbor)
+ */
+template< class Neighbor >
+class moOneMaxBitsIncrEval : public moEval<Neighbor>
+{
+public:
+    typedef typename Neighbor::EOT EOT;
+
+    /*
+    * incremental evaluation of the neighbor for the oneMax problem
+    * @param _solution the solution to move (bit string)
+    * @param _neighbor the neighbor to consider (of type moBitsNeigbor)
+    */
+    virtual void operator()(EOT & _solution, Neighbor & _neighbor) {
+      int delta = 0;
+
+      for(unsigned i = 0; i < _neighbor.bits.size(); i++) 	
+        if (_solution[_neighbor.bits[i]] == 0)
+	  delta++;
+        else
+          delta--;
+
+      _neighbor.fitness(_solution.fitness() + delta);
+    }
+};
+
+#endif
+