tpl_dynSlist.H

/* Aleph-w

     / \  | | ___ _ __ | |__      __      __
    / _ \ | |/ _ \ '_ \| '_ \ ____\ \ /\ / / Data structures & Algorithms
   / ___ \| |  __/ |_) | | | |_____\ V  V /  version 1.9b
  /_/   \_\_|\___| .__/|_| |_|      \_/\_/   https://github.com/lrleon/Aleph-w
                 |_|

  This file is part of Aleph-w library

  Copyright (c) 2002-2018 Leandro Rabindranath Leon & Alejandro Mujica

  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 <https://www.gnu.org/licenses/>.
*/

# ifndef TPL_DYNSLIST_H
# define TPL_DYNSLIST_H

# include <tpl_slist.H>

using namespace Aleph;

namespace Aleph {

  template <typename T>
  class DynSlist : public Slist<T>
  {
    size_t num_items;
    int        current_pos;
    Snode<T> * current_node;
    typename Slist<T>::Node * get_previous_to_pos(const int & pos)
    {
      if (pos > num_items)
        throw std::out_of_range ("position out of range");

      if (pos < current_pos) // hay que retroceder?
        { // Si, reinicie posición actual
          current_pos  = 0;
          current_node = this;
        }
      while (current_pos < pos)  // avanzar hasta nodo predecesor a pos
        {
          current_node = current_node->get_next();
          ++current_pos;
        }
      return current_node;
    }

  public:

    DynSlist() : num_items(0), current_pos(0), current_node(this)
    {
      // Empty
    }

    T & operator [] (const size_t & i)
    {
      return get_previous_to_pos(i)->get_next()->get_data();
    }

    size_t size() const { return num_items; }

    void insert(const int & pos, const T & data)
    {      // apartar nodo para nuevo elemento
      typename Slist<T>::Node * node = new typename Slist<T>::Node (data);
      typename Slist<T>::Node * prev = get_previous_to_pos(pos);
      prev->insert_next(node);
      ++num_items;
    }

    void remove(const int & pos)
    {      // obtener nodo predecesor al nuevo elemento
      typename Slist<T>::Node * prev = get_previous_to_pos(pos);
      typename Slist<T>::Node * node_to_delete = prev->remove_next();
      delete node_to_delete;
      --num_items;
    }

    virtual ~DynSlist()
    {      // eliminar nodo por nodo hasta que la lista devenga vacía
      while (not this->is_empty())
        delete this->remove_first_ne(); // remove_first de clase Slink
    }
    
    class Iterator : public Slist<T>::Iterator
    {
    public:
      typedef Slist<T> Set_Type;
      typedef T Item_Type;

      Iterator(DynSlist & list) : Slist<T>::Iterator(list) { /* Empty */ } 

      T & get_curr() { return Slist<T>::Iterator::get_curr()->get_data(); }
    };
  };

} // end namespace Aleph

# endif // TPL_DYNSLIST_H