/*-------------------------------------------------------------------------
           Program to demonstrate use of STL's deque container.
  ------------------------------------------------------------------------*/

#include <deque>
#include <iostream>;
using namespace std;

int main()
{
   deque<int> d;
  
   // Output number of values stored in d
   cout << d.size() << " elements in an empty deque\n";

   // Add first 6 integers alternately to front and back
   for (int i = 1; i <= 6; i += 2)
   {
      d.push_front(i);
      d.push_back(i+1);
   }
   cout << "Contents after alternating adds at front and back:\n";
   for (int i = 0; i < d.size(); i++)
      cout << d[i] << "  ";
   cout << endl;

   // Change back value to 999, remove front value;
   d.back() = 999; 
   d.pop_front();

   // Display contents of d again, but use an iterator
   cout << "Contents (via iterators) after changing back "
           "and popping front:\n";
   for (deque<int>::iterator it = d.begin(); 
                             it != d.end(); it++)
      cout << *it << "  ";
   cout << endl;

   // Dump contents of d from back to front
   cout << "Dumping the deque from the back:\n";
   while (!d.empty())
   {
      cout << d.back() << "  ";
      d.pop_back();
   }
   cout << endl;
   return 0;
}