paradiseo/mo/src/problems/bitString/moBitsWithoutReplNeighborhood.h

229 lines
7 KiB
C++

/*
<moBitsWithoutReplNeighborhood.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 use,
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".
As a counterpart to the access to the source code and rights to copy,
modify and redistribute granted by the license, users are provided only
with a limited warranty and the software's author, the holder of the
economic rights, and the successive licensors have only limited liability.
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 _moBitsWithoutReplNeighborhood_h
#define _moBitsWithoutReplNeighborhood_h
#include <neighborhood/moNeighborhood.h>
#include <problems/bitString/moBitsNeighborhood.h>
#include <utils/eoRNG.h>
#include <vector>
/**
* A neighborhood for bit string solutions
* where several bits could be flipped
* under a given Hamming distance
*
* The neighborhood is explored in a random order
* Each neighbors is visited once time
* and the number of visited neighbors is a parameter
*/
template< class Neighbor >
class moBitsWithoutReplNeighborhood : public moBitsNeighborhood<Neighbor>
{
using moBitsNeighborhood<Neighbor>::neighborhoodSize;
using moBitsNeighborhood<Neighbor>::length;
using moBitsNeighborhood<Neighbor>::nBits;
public:
/**
* Define type of a solution corresponding to Neighbor
*/
typedef typename Neighbor::EOT EOT;
/**
* Constructor
* @param _length bit string length
* @param _nBits maximum number of bits to flip (radius of the neighborhood)
* @param _sampleSize number of neighbor to sample in the neighborhood, if 0 all the neighborhood is sampled
* @param _exactDistance when true, only neighbor with exactly k bits flip are considered, other neighbor <= Hamming distance k
*/
moBitsWithoutReplNeighborhood(unsigned _length, unsigned _nBits, unsigned _sampleSize, bool _exactDistance = false): moBitsNeighborhood<Neighbor>(_length, _nBits, _exactDistance), sampleSize(_sampleSize) {
if (sampleSize > neighborhoodSize || sampleSize == 0)
sampleSize = neighborhoodSize;
indexVector.resize(neighborhoodSize);
for(unsigned int i = 0; i < neighborhoodSize; i++)
indexVector[i] = i;
/* all the neighbors */
if (neighborhoodSize >= 1000000) {
std::cout << "moBitsWithoutReplNeighborhood::Warning : the neighborhood size is larger than 10^6 : " << neighborhoodSize << std::endl;
}
int j;
bool last;
unsigned firstIndex;
if (_exactDistance)
firstIndex = nBits;
else
firstIndex = 1;
for(int d = firstIndex; d <= nBits; d++) {
std::vector<unsigned int> bits(d);
// the first one for this Hamming distance
for(unsigned i = 0; i < d; i++)
bits[i] = i;
neighborsVec.push_back(bits);
// the others ones
last = false;
while(!last) {
j = d - 1;
if (bits[j] < length - 1) {
bits[j]++;
neighborsVec.push_back(bits);
} else {
j--;
while ( (j >= 0) && (bits[j] + 1 == bits[j+1]) )
j--;
if (j < 0) {
last = true;
} else {
bits[j]++;
for(unsigned i = j+1; i < d; i++)
bits[i] = bits[i-1] + 1;
neighborsVec.push_back(bits);
}
}
}
}
if (neighborhoodSize != neighborsVec.size())
std::cout << "moBitsNeighborhood::Warning -> error in the neighborhood size computation, please check... : " << neighborhoodSize << " / " << neighborsVec.size() << std::endl;
}
/**
* Initialization of the neighborhood:
* apply several bit flips on the solution
* @param _solution the solution to explore
* @param _neighbor the first neighbor
*/
virtual void init(EOT & _solution, Neighbor & _neighbor) {
maxIndex = neighborhoodSize ;
unsigned i = rng.random(maxIndex);
key = indexVector[i];
unsigned tmp = indexVector[i];
indexVector[i] = indexVector[maxIndex - 1];
indexVector[maxIndex - 1] = tmp;
maxIndex--;
_neighbor.bits.resize(nBits);
setNeighbor(key, _neighbor);
}
/**
* Give the next neighbor
* apply several bit flips on the solution
* @param _solution the solution to explore (population of solutions)
* @param _neighbor the next neighbor which in order of distance
*/
virtual void next(EOT & _solution, Neighbor & _neighbor) {
unsigned i = rng.random(maxIndex);
key = indexVector[i];
unsigned tmp = indexVector[i];
indexVector[i] = indexVector[maxIndex - 1];
indexVector[maxIndex - 1] = tmp;
maxIndex--;
setNeighbor(key, _neighbor);
}
/**
* Test if all neighbors are explored or not,if false, there is no neighbor left to explore
* @param _solution the solution to explore
* @return true if there is again a neighbor to explore: population size larger or equals than 1
*/
virtual bool cont(EOT & _solution) {
return neighborhoodSize - maxIndex < sampleSize ;
}
/**
* Return the class Name
* @return the class name as a std::string
*/
virtual std::string className() const {
return "moBitsWithoutReplNeighborhood";
}
unsigned int index() {
return key;
}
protected:
// number of remainded neighbors to sample
unsigned int maxIndex;
// vector of possible index
std::vector<unsigned int> indexVector;
// maximum number of visited neighbor i.e. number of neighbor to sample in the neighborhood
unsigned int sampleSize;
// list of neighbors
std::vector< std::vector<unsigned int> > neighborsVec;
// key of the neighbor which is currently explored
unsigned int key;
/**
* Set the neighbor to the correct neighbor
* @param _key index in neighborVec of the neighbor to set
* @param _neighbor neighbor to set
*/
virtual void setNeighbor(unsigned _key, Neighbor & _neighbor) {
_neighbor.nBits = neighborsVec[_key].size();
for(unsigned i = 0; i < _neighbor.nBits; i++)
_neighbor.bits[i] = neighborsVec[_key][i];
}
};
#endif