bipartite_graph_coloring.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
 
// lal includes
#include <lal/basic_types.hpp>
#include <lal/detail/array.hpp>
 
namespace lal {
namespace properties {
 
class bipartite_graph_coloring {
public:
    typedef uint64_t color_t;
    static constexpr color_t invalid_color = 2;
    static constexpr color_t red = 0;
    static constexpr color_t blue = 1;
 
public:
    bipartite_graph_coloring() noexcept = default;
    bipartite_graph_coloring(const bipartite_graph_coloring&) noexcept = default;
    bipartite_graph_coloring(bipartite_graph_coloring&&) noexcept = default;
    bipartite_graph_coloring& operator= (const bipartite_graph_coloring&) noexcept = default;
    bipartite_graph_coloring& operator= (bipartite_graph_coloring&&) noexcept = default;
 
    bipartite_graph_coloring(std::size_t n) noexcept {
        init(n);
    }
 
    ~bipartite_graph_coloring() = default;
 
    void init(std::size_t n) noexcept {
        m_coloring.resize(n, invalid_color);
    }
 
    [[nodiscard]] bool is_color_valid(node u) const noexcept {
        return get_color_of(u) != invalid_color;
    }
 
    [[nodiscard]] std::size_t size() const noexcept { return m_coloring.size(); }
 
    [[nodiscard]] color_t get_color_of(node u) const noexcept { return m_coloring[u]; }
    [[nodiscard]] color_t& get_color_of(node u) noexcept { return m_coloring[u]; }
 
    [[nodiscard]] color_t operator[] (node u) const noexcept { return m_coloring[u]; }
    [[nodiscard]] color_t& operator[] (node u) noexcept { return m_coloring[u]; }
 
    [[nodiscard]] color_t operator[] (node_t u) const noexcept { return m_coloring[*u]; }
    [[nodiscard]] color_t& operator[] (node_t u) noexcept { return m_coloring[*u]; }
 
private:
    detail::array<color_t> m_coloring;
};
 
} // -- namespace properties
} // -- namespace lal