SinglePointCrossover.h

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#ifndef SINGLE_POINT_CROSSOVER_H
#define SINGLE_POINT_CROSSOVER_H
 
#pragma once
 
#include "Crossover.h"
#include "core/Individual.h"
#include <stdexcept>
#include <random>
#include <utility>
#include <algorithm>
 
namespace galib {
 
    template <typename GeneType>
    class SinglePointCrossover : public Crossover<GeneType> {
    public:
        SinglePointCrossover() = default;
 
        std::pair<Individual<GeneType>, Individual<GeneType>> crossover (
            const Individual<GeneType>& parent1, const Individual<GeneType>& parent2) override {
 
            const std::vector<GeneType>& parent1_genotype = parent1.getGenotype();
            const std::vector<GeneType>& parent2_genotype = parent2.getGenotype();
 
            if (parent1_genotype.size() != parent2_genotype.size()) {
                throw std::invalid_argument("Parents must have the same genotype length for crossover.");
            }
            std::size_t genotype_size = parent1_genotype.size();
 
            Individual<GeneType> child1 = parent1;
            Individual<GeneType> child2 = parent2;
 
            if (genotype_size > 1) {
                thread_local static std::random_device rd;
                thread_local static std::mt19937 gen(rd());
 
                std::uniform_int_distribution<std::size_t> distribution(1, genotype_size - 1);
                std::size_t crossover_point = distribution(gen);
 
                std::vector<GeneType>& child1_genotype = child1.getGenotype();
                std::vector<GeneType>& child2_genotype = child2.getGenotype();
 
                std::swap_ranges(
                    child1_genotype.begin() + crossover_point,
                    child1_genotype.end(),
                    child2_genotype.begin() + crossover_point
                );
            }
            return std::make_pair(child1, child2);
        }
    };
}
 
#endif // SINGLE_POINT_CROSSOVER_H