rand_bipartite_arrangements.hpp

/*********************************************************************
 *
 * Linear Arrangement Library - A library that implements a collection
 * algorithms for linear arrangments of graphs.
 *
 * Copyright (C) 2019 - 2024
 *
 * This file is part of Linear Arrangement Library. The full code is available
 * at:
 *      https://github.com/LAL-project/linear-arrangement-library.git
 *
 * Linear Arrangement Library is free software: you can redistribute it
 * and/or modify it under the terms of the GNU Affero General Public License
 * as published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * Linear Arrangement 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with Linear Arrangement Library.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Contact:
 *
 *     Lluís Alemany Puig (lluis.alemany.puig@upc.edu)
 *         LQMC (Quantitative, Mathematical, and Computational Linguisitcs)
 *         CQL (Complexity and Quantitative Linguistics Lab)
 *         Jordi Girona St 1-3, Campus Nord UPC, 08034 Barcelona.   CATALONIA, SPAIN
 *         Webpage: https://cqllab.upc.edu/people/lalemany/
 *
 *     Ramon Ferrer i Cancho (rferrericancho@cs.upc.edu)
 *         LQMC (Quantitative, Mathematical, and Computational Linguisitcs)
 *         CQL (Complexity and Quantitative Linguistics Lab)
 *         Office 220, Omega building
 *         Jordi Girona St 1-3, Campus Nord UPC, 08034 Barcelona.   CATALONIA, SPAIN
 *         Webpage: https://cqllab.upc.edu/people/rferrericancho/
 *
 ********************************************************************/
 
#pragma once
 
// C++ includes
#include <random>
 
// lal includes
#include <lal/linear_arrangement.hpp>
#include <lal/graphs/graph.hpp>
#include <lal/properties/bipartite_graph_coloring.hpp>
#include <lal/properties/bipartite_graph_colorability.hpp>
 
namespace lal {
namespace generate {
 
class rand_bipartite_arrangements {
public:
 
    template <class graph_t>
    rand_bipartite_arrangements(const graph_t& g, const uint64_t seed = 0) noexcept {
        static_assert(std::is_base_of_v<graphs::graph, graph_t>);
        m_coloring = properties::bipartite_coloring(g);
        init(seed);
    }
 
    rand_bipartite_arrangements(const rand_bipartite_arrangements& Gen) noexcept = default;
    rand_bipartite_arrangements(rand_bipartite_arrangements&& Gen) noexcept = default;
 
    rand_bipartite_arrangements
    (const properties::bipartite_graph_coloring& c, const uint64_t seed = 0)
    noexcept
    {
        m_coloring = c;
        init(seed);
    }
    rand_bipartite_arrangements
    (properties::bipartite_graph_coloring&& c, const uint64_t seed = 0)
    noexcept
    {
        m_coloring = std::move(c);
        init(seed);
    }
 
    [[nodiscard]] const linear_arrangement& get_arrangement() noexcept;
 
    [[nodiscard]] const linear_arrangement& yield_arrangement() noexcept {
        return get_arrangement();
    }
 
private:
    void init(const uint64_t seed) noexcept;
 
    void init_arrangement(const bool red_first) noexcept;
 
private:
    std::size_t m_n_blue;
    std::size_t m_n_red;
 
    std::mt19937 m_gen;
    std::bernoulli_distribution m_red_or_blue;
 
    linear_arrangement m_arr;
 
    properties::bipartite_graph_coloring m_coloring;
 
    properties::bipartite_graph_coloring::color_t m_what_in_left;
 
private:
    static constexpr properties::bipartite_graph_coloring::color_t blue =
        properties::bipartite_graph_coloring::blue;
    static constexpr properties::bipartite_graph_coloring::color_t red =
        properties::bipartite_graph_coloring::red;
};
 
} // -- namespace generate
} // -- namespace lal