9.3顺序容器操作

使用push_back()

将一个元素追加到尾部。
适合的容器有：除了array和forward_list外，每个顺序容器（包括string）都支持。

使用push_front

将一个元素追加到头部。
适合的容器有：list，forward_list和deque。

使用insert

在容器中任意位置插入0个或多个元素。
适合的容器有：vector，deque，list和string。forward_list提供了特殊的版本的insert成员。

//在顺序容器中添加元素
//c.push_back(t)
//c.push_front(t)
//c.insert(p,t)
//c.insert(p,n,t)
//c.insert(p,b,e)
//容器元素都是副本
//添加元素可能会使迭代器失效
//避免存储end操作返回的迭代器
#include<iostream>
#include <vector>
#include <list>
#include <string>
#include <deque>
using namespace std;

int main()
{
    vector<string> svec;
    list<string> slist;
    deque<string> sdeq;
    svec.push_back("bill");
    svec.push_back("tom");
    svec.push_back("mary");

    slist.push_back("bill");
    slist.push_back("tom");
    slist.push_back("mary");

    sdeq.push_back("bill");
    sdeq.push_back("tom");
    sdeq.push_back("mary");

    sdeq.push_front("primer");
    sdeq.push_front("c++");

    list<int> ilist;
    ilist.push_back(10);
    ilist.push_back(20);
    ilist.push_back(30);

    list<int>::iterator first = ilist.begin();
    while (first!=ilist.end())
    {
        ilist.insert(first, 42);
        ++first;
    }
    for (list<int>::iterator i = ilist.begin();
        i != ilist.end(); ++i)
        cout << *i << endl;
    cout << endl;
    for (list<string>::iterator iter = slist.begin();
        iter != slist.end(); ++iter)
        cout << *iter << endl;
    cout <<endl<<"++it:"<<endl;
    list<string>::iterator it = slist.begin();
    cout << *it << endl;
    ++it;
    cout <<endl<< *it << endl;
    cout <<endl<<"isert():"<< endl;
    slist.insert(it, 10, "hi");
    for (list<string>::iterator iter = slist.begin();
        iter != slist.end(); ++iter)
        cout << *iter << endl;

    cout << endl;
    string sarray[4] = { "qusai", "simba", "frollo", "scar" };
    it = slist.begin();
    cout << *it << endl;
    slist.insert(it, sarray + 1, sarray + 3);
    for (list<string>::iterator iter = slist.begin();
        iter != slist.end(); ++iter)
        cout << *iter << endl;
    cout << endl;
    return 0;
}

9.3.2访问元素

//访问元素
//c.back()
//c.front()
//c[n]
//c.at(n)
//c[n]和c.at(n)只合适vector和deque容器
#include <iostream>
#include <vector>
#include <list>
#include <deque>
using namespace std;


int main()
{
    vector<int> ivec;
    ivec.push_back(10);
    ivec.push_back(20);
    ivec.push_back(30);

    cout << endl;
    cout << ivec.front() << endl;
    cout << ivec.back() << endl;

    cout << endl;
    vector<int>::reference a = ivec.front();
    vector<int>::reference b = ivec.back();
    cout << a << endl;
    cout << b << endl;

    cout << endl;
    cout << *ivec.begin() << endl;
    cout << *--ivec.end() << endl;

    cout << endl;
    vector<int>::reference c = *ivec.begin();//返回一个引用
    vector<int>::reference d = *--ivec.end();
    cout << c << endl;
    cout << d << endl;

    cout << endl;
    cout << ivec[0] << endl;
    cout << ivec[1] << endl;
    cout << ivec[2] << endl;

    cout << endl;
    cout << ivec.at(0) << endl;
    cout << ivec.at(1) << endl;
    cout << ivec.at(2) << endl;
    try
    {
        cout << ivec.at(300) << endl;
    }
    catch (out_of_range)
    {
        cout << "出错了：下标越界。" << endl;
    }
    cout << endl;
    list<int> ilist;
    ilist.push_back(100);
    if (!ilist.empty())
    {
        cout << ilist.front() << endl;
        cout << ilist.back() << endl;
    }
    return 0;
}

9.3.3删除元素

pop_front和pop_back成员函数

pop_front和pop_back成员函数分别删除首元素和尾元素。vector和string不支持。

//删除容器
//c.erase(p)
//c.erase(b,e)
//c.clear()
//c.pop_back()
//c.pop_front()只适用于list和deque容器
#include<iostream>
#include <list>
#include <string>
using namespace std;

int main()
{
    list<string> slist;
    slist.push_back("apple");
    slist.push_back("bill");
    slist.push_back("cat");
    slist.push_back("dog");
    slist.push_back("egg");
    slist.push_back("fish");
    slist.push_back("girl");
    for (list<string>::iterator iter = slist.begin();
        iter != slist.end(); ++iter)
        cout << *iter << endl;
    slist.pop_front();
    slist.pop_back();
    string s1("dog");
    string s2("fish");
    list<string>::iterator iter1 = find(slist.begin(), slist.end(), s1);
    list<string>::iterator iter2 = find(slist.begin(), slist.end(), s2);
    if (iter1 != slist.end() && iter2 != slist.end())
        slist.erase(iter1, iter2);
    else
        cout << "没有找到" << endl;
    //if (iter != slist.end())
    //  slist.erase(iter);
    //else
    //  cout << "没有找到" << endl;
    slist.clear();
    if (!slist.empty())
    for (list<string>::iterator iter = slist.begin();
        iter != slist.end(); ++iter)
        cout << *iter << endl;
    else
        cout << "容器是空的！" << endl;
    return 0;
}