it.units.malelab.ege.ge.operator.LengthPreservingTwoPointsCrossover.java Source code

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Here is the source code for it.units.malelab.ege.ge.operator.LengthPreservingTwoPointsCrossover.java

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package it.units.malelab.ege.ge.operator;

import com.google.common.collect.Range;
import it.units.malelab.ege.ge.genotype.BitsGenotype;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

/**
 *
 * @author eric
 */
public class LengthPreservingTwoPointsCrossover extends TwoPointsCrossover {

    @Override
    public List<BitsGenotype> apply(List<BitsGenotype> parents, Random random) {
        BitsGenotype parent1 = parents.get(0);
        BitsGenotype parent2 = parents.get(1);
        int startIndex1 = Math.min(Math.max(1, random.nextInt(parent1.size())), parent1.size() - 2);
        int startIndex2 = Math.min(Math.max(1, random.nextInt(parent2.size())), parent2.size() - 2);
        int crossoverSize = Math.max(1,
                random.nextInt(Math.min(parent1.size() - startIndex1, parent2.size() - startIndex2)));
        int endIndex1 = startIndex1 + crossoverSize;
        int endIndex2 = startIndex2 + crossoverSize;
        return children(parent1, Range.closedOpen(startIndex1, endIndex1), parent2,
                Range.closedOpen(startIndex2, endIndex2));
    }

}