rand_ulab_free_trees.hpp

/*********************************************************************
 *
 *  Linear Arrangement Library - A library that implements a collection
 *  algorithms for linear arrangments of graphs.
 *
 *  Copyright (C) 2019 - 2021
 *
 *  This file is part of Linear Arrangement Library. To see the full code
 *  visit the webpage:
 *      https://github.com/lluisalemanypuig/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 (lalemany@cs.upc.edu)
 *          LARCA (Laboratory for Relational Algorithmics, Complexity and Learning)
 *          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)
 *          LARCA (Laboratory for Relational Algorithmics, Complexity and Learning)
 *          CQL (Complexity and Quantitative Linguistics Lab)
 *          Office S124, 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 <vector>
#include <map>
 
// lal includes
#include <lal/graphs/free_tree.hpp>
#include <lal/generate/rand_ulab_rooted_trees.hpp>
#include <lal/generate/tree_generator.hpp>
#include <lal/numeric/integer.hpp>
 
namespace lal {
namespace generate {
 
class _rand_ulab_free_trees : public _rand_ulab_rooted_trees {
public:
    /* CONSTRUCTORS */
 
    _rand_ulab_free_trees(uint32_t n, uint32_t seed = 0) noexcept;
    _rand_ulab_free_trees(const _rand_ulab_free_trees& Gen) = default;
#ifndef SWIG
    _rand_ulab_free_trees(_rand_ulab_free_trees&& Gen) = default;
#endif
    ~_rand_ulab_free_trees() = default;
 
    /* GETTERS */
 
    graphs::free_tree get_tree() noexcept;
 
protected:
    void init(uint32_t seed = 0) noexcept;
 
    void clear() noexcept;
 
private:
    std::map<std::pair<uint32_t, uint32_t>, numeric::integer> m_alpha;
 
    std::vector<numeric::integer> m_fn;
 
private:
    uint32_t forest(uint32_t m, uint32_t q, uint32_t nt) noexcept;
 
    void bicenter(uint32_t n) noexcept;
 
    const numeric::integer&
    get_alpha_mq(const uint32_t m, const uint32_t q) noexcept;
 
    void init_fn() noexcept;
 
    const numeric::integer& get_fn(const uint32_t n) noexcept;
 
    std::pair<uint32_t,uint32_t>
    choose_jd_from_alpha(const uint32_t m, const uint32_t q) noexcept;
};
 
class rand_ulab_free_trees : public _tree_generator<graphs::free_tree> {
public:
    /* CONSTRUCTORS */
 
    rand_ulab_free_trees(uint32_t n, uint32_t seed = 0) noexcept
        : _tree_generator<graphs::free_tree>(n), m_Gen(n, seed) { }
    rand_ulab_free_trees(const rand_ulab_free_trees& Gen) = default;
#ifndef SWIG
    rand_ulab_free_trees(rand_ulab_free_trees&& Gen) = default;
#endif
    ~rand_ulab_free_trees() = default;
 
    inline graphs::free_tree yield_tree() noexcept {
        return get_tree();
    }
 
protected:
    inline graphs::free_tree __get_tree() noexcept { return m_Gen.get_tree(); }
 
protected:
    _rand_ulab_free_trees m_Gen;
};
 
} // -- namespace generate
} // -- namespace lal