в 14:21, 25 мая 2010

2010-05-25T14:21:17Z

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2010-05-25T10:29:55Z

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==clear dq by popping elements one at a time==

<source lang="cpp">#include <iostream>
#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);
// clear dq by popping elements one at a time.
cout << "Front popping elements from dq.\n";
while(dq.size() > 0) {
cout << "Popping: " << dq.front() << endl;
dq.pop_front();
}
if(dq.empty()) cout << "dq is now empty.\n";
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>

==deque: constructor, size(), push_back(), pop_back(), begin(), end()==

<source lang="cpp">#include <iostream>
#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);
int sum = 0;
for(unsigned i=0; i < dq.size(); ++i) sum += dq[i];
double avg = sum / dq.size();
cout << avg << endl;
// Add elements to the end of dq.
dq.push_back(100);
dq.push_back(121);
show("dq after pushing elements onto the end: ", dq);
// Now use pop_back() to remove one element.
dq.pop_back();
show("dq after back-popping one element: ", dq);
cout << *dq.begin() << ", " << *(dq.end()-1) << "\n\n";
cout << *dq.rbegin() << ", " << *(dq.rend()-1) << "\n\n";
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>

==Remove first and last element==

<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.
*/
#include <iostream>
#include <deque>
#include <string>
#include <algorithm>
#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;
// remove first and last element
coll.pop_front();
coll.pop_back();
// print elements separated by newlines
copy (coll.begin(), coll.end(),ostream_iterator<string>(cout,"\n"));
cout << endl;
}</source>
<pre class=codeResult>first string
string
string
string
last string
string
string
string</pre>

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в 14:21, 25 мая 2010

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