tpl_random_queue.H

# ifndef TPL_RANDOM_QUEUE_H
# define TPL_RANDOM_QUEUE_H

# include <gsl/gsl_rng.h>
# include <tpl_dynArray.H>

namespace Aleph {

    template <class T> 
class Random_Set
{
private:

  DynArray<T> array;
  gsl_rng * r;

public:

  typedef Random_Set Set_Type;
  typedef T Item_Type;

  gsl_rng * get_rng() const { return r; }
  
  Random_Set() : array(0), r(NULL)
  {
    r = gsl_rng_alloc (gsl_rng_mt19937);
    if (r == NULL)
      throw std::bad_alloc();

    gsl_rng_set(r, time(NULL) % gsl_rng_max(r));
  }

  ~Random_Set()
  {
    if (r != NULL)
      gsl_rng_free(r);
  }

  void put(const T & item) { array[array.size()] = item; }

  T get()
  {
    if (array.size() == 0)
      throw std::underflow_error("Random set is empty");

    const size_t pos = gsl_rng_uniform_int(r, array.size()); // al azar
    T ret_val = array.access(pos);
    array.access(pos) = array.access(array.size() - 1);
    array.cut(array.size() - 1);
    return ret_val;
  }

  bool is_empty() const { return array.size() == 0; }
};

} // end namespace Aleph

# endif // TPL_RANDOM_QUEUE_H