STL-vector

#include <iostream>
#include <cstdio>
#include <vector>

using namespace std;

// 注意：vector在尾部添加或移动元素非常快，在中间操作非常耗时，因为它需要移动元素


int main()
{
    vector<int> v1;
    //push_back
    v1.push_back(1);
    //pop_back
    v1.push_back(2);
    // front,back,可以做左值
    cout<<v1.front()<<endl;
    cout<<v1.back()<<endl;
    // 左值
    v1.back()=5;

    for(vector<int>::iterator it=v1.begin();it!=v1.end();++it)
    {
        cout<<*it<<" ";
    }
    cout<<endl;

    v1.pop_back();

    for(vector<int>::iterator it=v1.begin();it!=v1.end();++it)
    {
        cout<<*it<<" ";
    }
    cout<<endl;


    // 以上是直接初始化方式
    // 还有以下三种初始化方式
    vector<int> v2=v1;

    vector<int> v3(v1.begin(),v1.begin()+1);
    vector<int> v4(v1.begin(),v1.end());

    vector<int> v5(3,9);

    for(vector<int>::iterator it=v5.begin();it!=v5.end();++it)
    {
        cout<<*it<<" ";
    }
    cout<<endl;


    for(int i=0;i<=5;++i)
    {
        v1.push_back(i);
    }

    // 用迭代器，逆向遍历
    for(vector<int>::reverse_iterator it=v1.rbegin();it!=v1.rend();it++)
    {
        cout<<*it<<" ";
    }
    cout<<endl;
    // 正向
    for(vector<int>::iterator it=v1.begin();it!=v1.end();++it)
    {
        cout<<*it<<" ";
    }
    cout<<endl;


    vector<int> v(10);
    cout<<v.size()<<endl;

    v.push_back(100);

    cout<<v.size()<<endl;
    for(vector<int>::iterator it=v.begin();it!=v.end();++it)
    {
        cout<<*it<<" ";
    }
    cout<<endl;

    // 删除
    for(vector<int>::iterator it=v1.begin();it!=v1.end();++it)
    {
        cout<<*it<<" ";
    }
    cout<<endl;
    v1.erase(v1.begin(),v1.begin()+3);
    for(vector<int>::iterator it=v1.begin();it!=v1.end();++it)
    {
        cout<<*it<<" ";
    }
    cout<<endl;

    v1.erase(v1.begin()+3);
    for(vector<int>::iterator it=v1.begin();it!=v1.end();++it)
    {
        cout<<*it<<" ";
    }
    cout<<endl;


    // 插入
    v1.insert(v1.begin()+2,10);
    for(vector<int>::iterator it=v1.begin();it!=v1.end();++it)
    {
        cout<<*it<<" ";
    }
    cout<<endl;

    v1.insert(v1.begin()+1,3,33);
    for(vector<int>::iterator it=v1.begin();it!=v1.end();++it)
    {
        cout<<*it<<" ";
    }
    cout<<endl;


    return 0;
}