tree.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
#if defined DEBUG
#include <cassert>
#endif
#include <string>
#include <vector>
#include <array>
 
// lal includes
#include <lal/graphs/graph.hpp>
#include <lal/graphs/tree_type.hpp>
 
namespace lal {
namespace graphs {
 
class tree : virtual public graph {
public:
    /* CONSTRUCTORS */
 
    tree() noexcept { }
    tree(const tree& t) noexcept : graph() {
        tree_only_copy(t);
    }
#ifndef SWIG
    tree(tree&& t) noexcept {
        tree_only_move(std::move(t));
    }
#endif
    virtual ~tree() noexcept { }
 
    /* OPERATORS */
 
#ifndef SWIG
    tree& operator= (const tree& t) noexcept {
        tree_only_copy(t);
        return *this;
    }
    tree& operator= (tree&& t) noexcept {
        tree_only_move(std::move(t));
        return *this;
    }
#endif
 
    /* MODIFIERS */
 
    virtual void calculate_tree_type() noexcept = 0;
 
    /* GETTERS */
 
    bool is_tree() const noexcept {
        // NOTE: this would not really be true if the addition of edges
        // was not constrained. Since it is, in a way that no cycles can
        // be produced, then we only need to check for the number of edges.
        return (get_num_nodes() == 0 ? true : get_num_edges() == get_num_nodes() - 1);
 
        // NOTE 2: this is only true in a debug compilation of the library
        // since a release compilation does not actually constrain the addition
        // of edges
    }
 
    virtual bool is_rooted() const noexcept = 0;
 
    bool can_add_edge(node s, node t) const noexcept;
 
    bool can_add_edges(const std::vector<edge>& edges) const noexcept;
 
    inline uint32_t get_num_nodes_component(node u) const noexcept {
#if defined DEBUG
        assert(has_node(u));
#endif
        return m_root_size[m_root_of[u]];
    }
 
    inline bool is_of_tree_type(const tree_type& tt) const noexcept {
        return m_tree_type[static_cast<std::size_t>(tt)];
    }
 
    inline bool is_tree_type_valid() const noexcept { return m_is_tree_type_valid; }
 
    std::vector<std::string> get_tree_type_list() const noexcept;
 
protected:
    std::vector<node> m_root_of;
    std::vector<uint32_t> m_root_size;
 
    std::array<bool,__tree_type_size> m_tree_type;
    bool m_is_tree_type_valid = false;
 
protected:
    void tree_only_init(uint32_t n) noexcept;
    void tree_only_clear() noexcept;
 
    void tree_only_copy(const tree& t) noexcept;
    void tree_only_move(tree&& t) noexcept;
 
    void extra_work_per_edge_add(node u, node v) noexcept;
    void extra_work_per_edge_remove(node u, node v) noexcept;
 
    void tree_only_extra_work_edges_set() noexcept;
 
    void fill_union_find() noexcept;
 
    virtual void call_union_find_after_add(
        node u, node v,
        uint32_t * const root_of, uint32_t * const root_size
    ) noexcept = 0;
    virtual void call_union_find_after_add(
        node u, node v,
        uint32_t * const root_of, uint32_t * const root_size
    ) const noexcept = 0;
    virtual void call_union_find_after_remove(
        node u, node v,
        uint32_t * const root_of, uint32_t * const root_size
    ) noexcept = 0;
    virtual void call_union_find_after_remove(
        node u, node v,
        uint32_t * const root_of, uint32_t * const root_size
    ) const noexcept = 0;
};
 
} // -- namespace graphs
} // -- namespace lal