// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-

//-----------------------------------------------------------------------------
// FlowShopOpCrossoverQuad.h
// (c) OPAC Team (LIFL), Dolphin Project (INRIA), 2007
/*
    This library...

    Contact: paradiseo-help@lists.gforge.inria.fr, http://paradiseo.gforge.inria.fr
 */
//-----------------------------------------------------------------------------

#ifndef FLOWSHOPOPMUTATIONEXCHANGE_H_
#define FLOWSHOPOPMUTATIONEXCHANGE_H_

#include <eoOp.h>
#include "FlowShop.h"

/**
 * Functor
 * Exchange mutation operator for flow-shop
 */
class FlowShopOpMutationExchange: public eoMonOp<FlowShop> {

public:

    /**
     * default constructor
     */
    FlowShopOpMutationExchange() {}

    /**
     * the class name (used to display statistics)
     */
    string className() const {
        return "FlowShopOpMutationExchange";
    }

    /**
     * modifies the parent with an exchange mutation
     * @param FlowShop & _genotype  the parent genotype (will be modified)
     */
    bool operator()(FlowShop & _genotype) {
        bool isModified;

        // schedulings
        vector<unsigned> initScheduling   = _genotype.getScheduling();
        vector<unsigned> resultScheduling = _genotype.getScheduling();

        // computation of the 2 random points
        unsigned point1, point2;
        do {
            point1 = rng.random(resultScheduling.size());
            point2 = rng.random(resultScheduling.size());
        } while (point1 == point2);

        // swap
        swap (resultScheduling[point1], resultScheduling[point2]);

        // update (if necessary)
        if (resultScheduling != initScheduling) {
            // update
            _genotype.setScheduling(resultScheduling);
            // the genotype has been modified
            isModified = true;
        }
        else {
            // the genotype has not been modified
            isModified = false;
        }

        // return 'true' if the genotype has been modified
        return isModified;
    }

};

#endif /*FLOWSHOPOPMUTATIONEXCHANGE_H_*/