tpl_graph_indexes.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_GRAPH_INDEXES_H
# define TPL_GRAPH_INDEXES_H
 
# include <tpl_dynSetTree.H>
# include <tpl_graph.H>
 
using namespace Aleph;
 
namespace Aleph
{
 
template <class GT>
struct Dft_Node_Cmp
{
  bool operator () (typename GT::Node * p1, typename GT::Node * p2) const
  {
    return p1->get_info() < p2->get_info();
  }
};
 
template <class GT>
struct Dft_Arc_Cmp
{
  bool operator () (typename GT::Arc * a1, typename GT::Arc * a2) const
  {
    if (a1->src_node < a2->src_node)
      return true;
 
    return not (a2->src_node < a1->src_node) and a1->tgt_node < a2->tgt_node;
  }
};
 
template <class GT, class Compare = Dft_Node_Cmp<GT>,
          template <typename, class> class Tree = Treap,
          class SN = Dft_Show_Node<GT>>
class Nodes_Index : public DynSetTree<typename GT::Node *, Tree, Compare>
{
  typedef typename GT::Node GT_Node;
  
  typedef typename GT::Node_Type GT_Node_Info;
  
  typedef DynSetTree <GT_Node *, Tree, Compare> Tree_Type;
 
  GT & g;
  
  SN & sn;
 
  void init()
  {
    for (Node_Iterator<GT, SN> it(g, sn); it.has_curr(); it.next_ne())
      this->insert(it.get_curr());
  }
 
public:
  Nodes_Index(GT & _g, Compare & cmp, SN & _sn)
    : Tree_Type(cmp), g(_g), sn(_sn)
  {
    init();
  }
 
  Nodes_Index(GT & _g, Compare && cmp = Compare(), SN && _sn = SN())
    : Tree_Type(cmp), g(_g), sn(_sn)
  {
    init();
  }
 
  GT_Node * insert_in_graph(GT_Node * p)
  {
    g.insert_node(p);
 
    if (this->insert(p) == nullptr)
      {
        g.remove_node(p);
        return nullptr;
      }
 
    return p;
  }
 
  GT_Node * search_or_insert_in_graph(GT_Node * p)
  {
    g.insert_node(p);
    GT_Node ** ptr_node = this->search_or_insert(p);
    GT_Node * q = *ptr_node;
 
    if (p != q)
      g.remove_node(p);
 
    return q;
  }
 
  GT_Node * insert_in_graph(const GT_Node_Info & info)
  {
    GT_Node * p = g.insert_node(info);
    
    if (this->insert(p) == nullptr)
      {
        g.remove_node(p);
        return nullptr;
      }
 
    return p;
  }
 
  GT_Node * search_or_insert_in_graph(const GT_Node_Info & info)
  {
    GT_Node * p = g.insert_node(info);
    GT_Node ** ptr_node = this->search_or_insert(p);
    GT_Node * q = *ptr_node;
 
    if (p != q)
      g.remove_node(p);
 
    return q;
  }
 
  GT_Node * insert_in_graph(const GT_Node_Info && info = GT_Node_Info())
  {
    return insert_in_graph(info);
  }
 
  GT_Node * search(GT_Node * p)
  {
    GT_Node ** ret_val = Tree_Type::search(p);
 
    if (ret_val == nullptr)
      return nullptr;
 
    return *ret_val;
  }
 
  GT_Node * search(const GT_Node_Info & info)
  {
    GT_Node dummy_node(info);
    GT_Node * dummy_node_ptr = &dummy_node;
 
    return search(dummy_node_ptr);
  }
 
  void remove_from_graph(GT_Node * p)
  {
    Tree_Type::find(p); // throws exception if p is not in the index
    Tree_Type::remove(p);
    g.remove_node(p);
  }
};
 
template <class GT, class Compare = Dft_Arc_Cmp<GT>,
          template <typename, class> class Tree = Treap,
          class SA = Dft_Show_Arc<GT>>
class Arcs_Index : public DynSetTree<typename GT::Arc *, Tree, Compare>
{
  typedef typename GT::Node GT_Node;
  
  typedef typename GT::Node_Type GT_Node_Info;
  
  typedef typename GT::Arc GT_Arc;
  
  typedef typename GT::Arc_Type GT_Arc_Info;
  
  typedef DynSetTree <typename GT::Arc *, Tree, Compare> Tree_Type;
 
  GT & g;
  
  SA & sa;
 
  void init()
  {
    for (Arc_Iterator<GT, SA> it(g, sa); it.has_curr(); it.next_ne())
      this->insert(it.get_curr());
  }
 
public:
  Arcs_Index(GT & _g, Compare & cmp, SA & _sa)
    : Tree_Type(cmp), g(_g), sa(_sa)
  {
    init();
  }
 
  Arcs_Index(GT & _g, Compare && cmp = Compare(), SA && _sa = SA())
    : Tree_Type(cmp), g(_g), sa(_sa)
  {
    init();
  }
 
  GT_Arc * insert_in_graph(GT_Node * src, GT_Node * tgt,
                           const GT_Arc_Info & info)
  {
    GT_Arc * a = g.insert_arc(src, tgt, info);
    
    if (this->insert(a) == nullptr)
      {
        g.remove_arc(a);
        return nullptr;
      }
 
    return a;
  }
 
  GT_Arc * insert_in_graph(GT_Node * src, GT_Node * tgt,
                           const GT_Arc_Info && info = GT_Arc_Info())
  {
    return insert_in_graph(src, tgt, info);
  }
 
  GT_Arc * search(GT_Node * src, GT_Node * tgt, const GT_Arc_Info & info)
  {
    // Create persistent key for search (avoid stack allocation)
    auto * key = new GT_Arc(info);
    key->src_node = src;
    key->tgt_node = tgt;
    
    GT_Arc ** ret_val = Tree_Type::search(key);
    
    if (ret_val != nullptr)
      {
        GT_Arc* found = *ret_val;
        delete key;
        return found;
      }
    
    if (g.is_digraph())
      {
        delete key;
        return nullptr;
      }
    
    // Try reverse direction for undirected graphs
    std::swap(key->src_node, key->tgt_node);
    ret_val = Tree_Type::search(key);
    
    if (ret_val == nullptr)
      {
        delete key;
        return nullptr;
      }
    
    // Validate arc direction consistency
    GT_Arc* found = *ret_val;
    assert(((src == found->src_node) && (tgt == found->tgt_node)) || 
           ((tgt == found->src_node) && (src == found->tgt_node)));
    
    delete key;
    return found;
  }
 
  GT_Arc * search(GT_Node * src, GT_Node * tgt,
                  const GT_Arc_Info && info = GT_Arc_Info())
  {
    return search(src, tgt, info);
  }
 
  void remove_from_graph(GT_Arc * a)
  {
    Tree_Type::find(a);
    Tree_Type::remove(a);
    g.remove_arc(a);
  }
 
};
 
} // End namespace Aleph
 
# endif // GRAPH_INDEXES_H