lca_lookup.hpp

Go to the documentation of this file.

#ifndef GENESIS_TREE_FUNCTION_LCA_LOOKUP_H_
#define GENESIS_TREE_FUNCTION_LCA_LOOKUP_H_

/*
    Genesis - A toolkit for working with phylogenetic data.
    Copyright (C) 2014-2019 Lucas Czech and HITS gGmbH

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

    Contact:
    Lucas Czech <lucas.czech@h-its.org>
    Exelixis Lab, Heidelberg Institute for Theoretical Studies
    Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg, Germany
*/

#include "genesis/utils/math/range_minimum_query.hpp"

#include <vector>

namespace genesis {
namespace tree {

// =================================================================================================
//     Forward Declarations
// =================================================================================================

class Tree;
class TreeNode;

// =================================================================================================
//     LCA Lookup
// =================================================================================================

class LcaLookup
{
public:

    // -------------------------------------------------------------------------
    //     Construction and Rule of Five
    // -------------------------------------------------------------------------

    LcaLookup() = default;
    explicit LcaLookup( Tree const& tree );

    ~LcaLookup() = default;

    LcaLookup( LcaLookup const& other ) = default;
    LcaLookup( LcaLookup&& )            = default;

    LcaLookup& operator= ( LcaLookup const& other ) = default;
    LcaLookup& operator= ( LcaLookup&& )            = default;

    // -------------------------------------------------------------------------
    //     Lookup
    // -------------------------------------------------------------------------

    std::size_t operator()( size_t node_index_a, size_t node_index_b, size_t root_index ) const;
    TreeNode const& operator()( TreeNode const& node_a, TreeNode const& node_b, TreeNode const& root_node ) const;

    size_t operator()( size_t node_index_a, size_t node_index_b ) const;
    TreeNode const& operator()( TreeNode const& node_a, TreeNode const& node_b ) const;

    // -------------------------------------------------------------------------
    //     Internal Helper Functions
    // -------------------------------------------------------------------------

private:

    void init_( Tree const& tree );

    size_t eulertour_query_( size_t i, size_t j ) const;

    size_t lookup_( size_t node_index_a, size_t node_index_b, size_t root_index ) const;

    // -------------------------------------------------------------------------
    //     Data Members
    // -------------------------------------------------------------------------

private:

    utils::RangeMinimumQuery eulertour_rmq_;

    std::vector<size_t> eulertour_order_;

    std::vector<size_t> eulertour_first_occurrence_;

    Tree const* tree_ = nullptr;
    size_t      root_idx_;
};

} // namespace tree
} // namespace genesis

#endif // include guard