C++ 双端队列_c++中双端队列的操作

双端队列的基本操作

pop_back()    	//尾部删除
pop_front()		//头部删除
push_back()		//尾部插入
push_front()	//头部插入
insert()		//指定位置插入
erase();		//指定位置删除
clear()			//清空队列

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#include "deque.h"
#include <deque>
#include <iostream>
using namespace std;

/*
基本函数
pop_back()
pop_front()
push_back()
push_front()
insert()
erase();
clear()
*/
//使用push_back()方法从尾部插入元素，会不断扩张队列。
void tail_insert()
{

    deque<int>q;
    for(int i = 0;i<5;i++)
    {
        q.push_back(i);
    }
    for(int i = 0;i<5;i++)
    {
        cout<<q[i]<<" ";
    }
    cout<<endl;

}

//从头部插入元素，也会扩张队列。
void front_insert()
{
    deque<int>q;
    q.push_back(1);
    q.push_back(2);
    q.push_back(3);
    q.push_front(10);  //相当于q.insert(q.begin()+1,10);
    q.push_front(20);  //相当于q.insert(q.begin()+2,10);

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

void deque_traverse()
{
    deque<int>q;
    q.push_back(1);
    q.push_back(2);
    q.push_back(3);
    q.push_front(10);  //相当于q.insert(q.begin()+1,10);
    q.push_front(20);  //相当于q.insert(q.begin()+2,10);

    //顺序遍历
deque<int>::iterator it;
for(it =q.begin();it!= q.end();it++ )
{
    cout<<*it<<" ";
}
cout<<endl;

//逆序遍历
deque<int>::reverse_iterator rit;
for(rit  =q.rbegin();rit != q.rend();rit++)
{
     cout<<*rit<<" ";
}
cout<<endl;
}


//可以从双端队列的手部，尾部，中部删除元素，并可以清空双端队列容器
void control_deque()
{

    deque<int>q;
    q.push_back(1);
    q.push_back(2);
    q.push_back(3);
    q.push_front(10);  //相当于q.insert(q.begin()+1,10);
    q.push_front(20);  //相当于q.insert(q.begin()+2,10);

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

    //删除队尾元素
    q.pop_back();
    cout<<" pop_back():";

    for(it =q.begin();it!= q.end();it++ )
    {
        cout<<*it<<" ";
    }
    cout<<endl;

    //删除队首元素
    q.pop_front();
    cout<<" pop_front():";
    for(it =q.begin();it!= q.end();it++ )
    {
        cout<<*it<<" ";
    }
    cout<<endl;

    //删除队列中下标为2的位置元素 参数为指针
    q.erase(q.begin()+2);
    cout<<" erase():";

    for(it =q.begin();it!= q.end();it++ )
    {
        cout<<*it<<" ";
    }
    cout<<endl;

    //在下标为1处添加新元素8
    q.insert(q.begin()+1,8);
    cout<<" insert():";
    for(it =q.begin();it!= q.end();it++ )
    {
        cout<<*it<<" ";
    }
    cout<<endl;

    //清空队列
    q.clear();
    cout<<" clear():";
    cout<<" size():"<<q.size();
    cout<<endl;

}
void deque_test()
{
tail_insert();

front_insert();

deque_traverse();

control_deque();
}

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int main()
{
    deque_test();
    return 0;
}
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输出

0 1 2 3 4
20 10 1 2 3
20 10 1 2 3
3 2 1 10 20
 control_deque():20 10 1 2 3
 pop_back():20 10 1 2
 pop_front():10 1 2
 erase():10 1
 insert():10 8 1
 clear(): size():0
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