C++ Tutorial/deque/deque push

Push an element onto the front of deque

<source lang="cpp">#include <iostream>

1. include <deque>

using namespace std; void show(const char *msg, deque<int> q); int main() {

 deque<int> dq(10);
 for(unsigned i=0; i < dq.size(); ++i) dq[i] = i*i;
 show("Contents of dq: ", dq);
 // Push an element onto the front of dq.
 dq.push_front(-31416);
 show("dq after call to push_front(): ", dq);
 cout <<endl;
 return 0;

} // Display the contents of a deque<int>. void show(const char *msg, deque<int> q) {

 cout << msg;
 for(unsigned i=0; i < q.size(); ++i)
   cout << q[i] << " ";
 cout << "\n";

}</source>

Push element into deque and print all elements

<source lang="cpp">/* The following code example is taken from the book

* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/

1. include <iostream>
2. include <deque>

using namespace std; int main() {

   deque<float> coll;    // deque container for floating-point elements
   // insert elements from 1.1 to 6.6 each at the front
   for (int i=1; i<=6; ++i) {
       coll.push_front(i*1.1);      // insert at the front
   }
   // print all elements followed by a space
   for (int i=0; i<coll.size(); ++i) {
       cout << coll[i] << " ";
   }
   cout << endl;

}</source>

6.6 5.5 4.4 3.3 2.2 1.1

STL deque: push_back(), push_front(), pop_back(), pop_front()

<source lang="cpp">#include <deque>

#include <iostream>
#include <algorithm>
int main ()
{
    using namespace std;
    deque <int> dqIntegers;
    dqIntegers.push_back (3);
    dqIntegers.push_back (4);
    dqIntegers.push_back (5);
    dqIntegers.push_front (2);
    dqIntegers.push_front (1);
    dqIntegers.push_front (0);
    for ( size_t nCount = 0; nCount < dqIntegers.size (); ++ nCount ){
        cout << "Element [" << nCount << "] = ";
        cout << dqIntegers [nCount] << endl;
    }
    // Erase an element at the top
    dqIntegers.pop_front ();
    // Erase an element at the bottom
    dqIntegers.pop_back ();
    deque <int>::iterator iElementLocator;
    for ( iElementLocator = dqIntegers.begin (); iElementLocator != dqIntegers.end (); ++ iElementLocator )
    {
        size_t nOffset = distance (dqIntegers.begin (), iElementLocator);
        cout<<"Element [" << nOffset << "] = " << *iElementLocator<<endl;
    }
    return 0;

}</source>

Use assign and push_back, push_front to insert element to a deque

<source lang="cpp">/* The following code example is taken from the book

* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/

1. include <iostream>
2. include <deque>
3. include <string>
4. include <algorithm>
5. include <iterator>

using namespace std; int main() {

   // create empty deque of strings
   deque<string> coll;
   // insert several elements
   coll.assign (3, string("string"));
   coll.push_back ("last string");
   coll.push_front ("first string");
   // print elements separated by newlines
   copy (coll.begin(), coll.end(),
         ostream_iterator<string>(cout,"\n"));
   cout << endl;

}</source>

first string
string
string
string
last string