// Catalano Genetic Library
// The Catalano Framework
//
// Copyright © Diego Catalano, 2012-2019
// diego.catalano at live.com
//
//
//    This library is free software; you can redistribute it and/or
//    modify it under the terms of the GNU Lesser General Public
//    License as published by the Free Software Foundation; either
//    version 2.1 of the License, or (at your option) any later version.
//
//    This library is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//    Lesser General Public License for more details.
//
//    You should have received a copy of the GNU Lesser General Public
//    License along with this library; if not, write to the Free Software
//    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
//

package Catalano.Evolutionary.Genetic.Selection;

import Catalano.Core.ArraysUtil;
import Catalano.Evolutionary.Genetic.Chromosome.IChromosome;
import java.util.Arrays;
import java.util.List;

/**
 * Elitism Selection.
 * @author Diego Catalano
 */
public class ElitismSelection implements ISelection, IRealCodedSelection{

    /**
     * Initializes a new instance of the ElitismSelection class.
     */
    public ElitismSelection() {}

    @Override
    public int[] Compute(List chromossomes) {
        
        //Sort the chromossomes
        double[] fitness = new double[chromossomes.size()];
        for (int i = 0; i < chromossomes.size(); i++) {
            fitness[i] = chromossomes.get(i).getFitness();
        }
        
        int[] index = ArraysUtil.Argsort(fitness, false);
        
        return Arrays.copyOfRange(index, 0, 2);
        
    }

    @Override
    public int[] Compute(double[] fitness) {
        int[] order = ArraysUtil.Argsort(fitness, false);
        return Arrays.copyOf(order, 2);
    }
    
}