//插入元素//
#include<iostream>
 #include<deque>
 using namespace std;

 int main()
 {
    deque<int> d;

    d.push_back(1);//尾部插入
    d.push_back(2);
    d.push_back(3);
    d.push_front(10);//d.insert(d.begin()+1, 10);头部插入
    d.push_front(20);//d.insert(d.begin()+2, 20);

    cout<<d[0]<<" "<<d[1]<<" "<<d[2]<<endl;

    return 0;
 }

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

 int main()
 {
    deque<int> d;
    d.push_back(1);
    d.push_back(2);
    d.push_back(3);

    for(int i = 0; i < d.size(); i ++)
        cout<<d[i]<<" ";
    cout<<endl;

    deque<int>::iterator it;
    for(it = d.begin(); it != d.end(); it ++)
        cout<<*it<<" ";
    cout<<endl;

    deque<int>::reverse_iterator rit;
    for(rit = d.rbegin(); rit != d.rend(); rit ++)
        cout<<*rit<<" ";//反向遍历
    cout<<endl;

    return 0;
 }

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

int main()
{
    deque<int> d;
    for(int i = 1; i < 6; i ++)
        d.push_back(i);

    d.pop_front();
    d.pop_front();

    deque<int>::iterator it;
    for(it = d.begin(); it != d.end(); it ++)
        cout<<*it<<" ";
    cout<<endl;

    d.pop_back();
    for(it = d.begin(); it != d.end(); it ++)
        cout<<*it<<" ";
    cout<<endl;

    d.erase(d.begin()+1);
    for(it = d.begin(); it != d.end(); it ++)
        cout<<*it<<" ";
    cout<<endl;

    d.clear();
    cout<<d.size()<<endl;

    return 0;
}