tpl_indexArc.H

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/*
                          Aleph_w
 
  Data structures & Algorithms
  version 2.0.0b
  https://github.com/lrleon/Aleph-w
 
  This file is part of Aleph-w library
 
  Copyright (c) 2002-2026 Leandro Rabindranath Leon
 
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
 
  The above copyright notice and this permission notice shall be included in all
  copies or substantial portions of the Software.
 
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  SOFTWARE.
*/
 
 
# ifndef TPL_INDEXARC_H
# define TPL_INDEXARC_H
 
# include <cassert>
# include <functional>
# include <stdexcept>
# include <utility>
 
# include <tpl_dynSetTree.H>
# include <tpl_graph.H>
# include <ah-errors.H>
 
using namespace Aleph;
 
namespace Aleph
{
 
 
  template <
    class GT,
    template <class /* Key */, class /* Compare */> class Tree = Rand_Tree,
    class SA = Dft_Show_Arc<GT>
    >
  class IndexArc
  {
  private:
 
    typedef typename GT::Arc GT_Arc;
    typedef typename GT::Node GT_Node;
    typedef typename GT::Arc_Type GT_Arc_Type;
    typedef typename GT::Node_Type GT_Node_Type;
 
    struct Cmp_Arc
    {
      bool directed = false;
 
      static bool ptr_less(void * a, void * b) noexcept
      {
        return std::less<void*>{}(a, b);
      }
 
      Cmp_Arc() = default;
 
      explicit Cmp_Arc(bool __directed) noexcept : directed(__directed) {}
 
      static std::pair<void*, void*> endpoints(const GT_Arc * a, const bool directed) noexcept
      {
        if (directed)
          return { a->src_node, a->tgt_node };
 
        auto u = a->src_node;
        auto v = a->tgt_node;
        if (ptr_less(v, u))
          std::swap(u, v);
        return {u, v};
      }
 
      bool operator () (const GT_Arc * a1, const GT_Arc * a2) const
      {
        const auto e1 = endpoints(a1, directed);
        const auto e2 = endpoints(a2, directed);
        if (ptr_less(e1.first, e2.first))
          return true;
        if (ptr_less(e2.first, e1.first))
          return false;
        return ptr_less(e1.second, e2.second);
      }
    };
 
    GT & g;
    DynSetTree <GT_Arc *, Tree, Cmp_Arc> index;
    SA sa;
 
  public:
 
    GT_Arc * insert(GT_Arc * e)
    {
      auto p = index.contains_or_insert(e);
      return *p.first;
    }
 
    GT_Arc * search(void * src, void * tgt) const
    {
      GT_Arc arc;
      arc.src_node = src;
      arc.tgt_node = tgt;
 
      GT_Arc ** ret_val = index.search(&arc);
 
      return ret_val != nullptr ? *ret_val : nullptr;
    }
 
    GT_Arc * search_directed(void * src, void * tgt) const
    {
      GT_Arc arc;
      arc.src_node = src;
      arc.tgt_node = tgt;
 
      GT_Arc ** ret_val = index.search(&arc);
 
      return ret_val != nullptr ? *ret_val : nullptr;
    }
 
    GT_Arc * search(GT_Arc * a) const
    {
      return search(a->src_node, a->tgt_node);
    }
 
    GT_Arc * insert_in_graph(GT_Node * src, GT_Node * tgt,
                             const GT_Arc_Type & info)
    {
      GT_Arc * a = search(src, tgt);
 
      ah_domain_error_if(a != nullptr)
        << "There is already an arc between these nodes";
 
      a = g.insert_arc(src, tgt, info);
      insert(a);
 
      return a;
    }
 
    GT_Arc * insert_in_graph(GT_Node * src, GT_Node * tgt,
                             GT_Arc_Type && info = GT_Arc_Type())
    {
      GT_Arc * a = search(src, tgt);
 
      ah_domain_error_if(a != nullptr)
        << "There is already an arc between these nodes";
 
      a = g.insert_arc(src, tgt, std::forward<GT_Arc_Type>(info));
      insert(a);
 
      return a;
    }
 
    void remove(GT_Arc * e)
    {
      index.remove(e);
    }
 
    void remove_from_graph(GT_Arc * a)
    {
      remove(a);
      g.remove_arc(a);
    }
 
    void clear_index()
    {
      index.empty();
    }
 
    void build_index()
    {
      for (Arc_Iterator<GT, SA> it(g, sa); it.has_curr(); it.next_ne())
          if (GT_Arc * a = it.get_curr(); search(a) == nullptr)
            insert(a);
    }
 
  private:
 
    void init()
    {
      for (Arc_Iterator<GT, SA> it(g, sa); it.has_curr(); it.next_ne())
        insert(it.get_curr());
    }
 
  public:
 
    IndexArc(GT & __g, bool with_init = true, SA && __sa = SA())
      : g(__g), index(Cmp_Arc(__g.is_digraph())), sa(std::move(__sa))
    {
      if (with_init)
        init();
    }
 
    IndexArc(GT & __g, bool with_init, SA & __sa)
      : g(__g), index(Cmp_Arc(__g.is_digraph())), sa(__sa)
    {
      if (with_init)
        init();
    }
 
    size_t size() const { return index.size(); }
  };
 
}
 
# endif