STL里容器vector部分用法

//test.cpp
#include<iostream>
#include<vector>
using namespace std;
int main()
{
    vector<int> v;
    vector<int> v1(10);//为向量v1赋值10个0
    vector<int> v3(10, 100);//为向量v3赋值10个100
    for(int i=1; i<8; ++i)
    {
        v.push_back(i);
        v1.push_back(i);
    }
    vector<int>::iterator it = v.begin();//迭代器，指向向量头部
    cout<<"v = ";
    while(it!=v.end())
    {
        cout<<*it<<" ";
        ++it;
    }
    cout<<endl;


    vector<int>::reverse_iterator rv_it = v1.rbegin();//反向迭代器，指向向量尾部，且自加时是向向量头部移动：
    cout<<"rv_v1 = ";
    while(rv_it != v1.rend())
    {
        cout<<*rv_it<<" ";
        ++rv_it;
    }
    cout<<endl;

    v3.insert(v3.begin()+3, 7);//在v3第三个元素前插入7
    v3.insert(v3.begin()+1, 2, 8);//在v3第二个元素前插入2个8
    vector<int>::iterator first = v.begin()+3;
    vector<int>::iterator end = v.end();
    v3.insert(v3.end(), first, end);//在v3.end()后将区间[v1.begin()+3, v1.end())元素全部插入:
    vector<int>::iterator it3 = v3.begin();
    v3.erase(v3.begin()+1);//删除v3第二个元素
    cout<<"v3 = ";
    while(it3 != v3.end())
    {
        cout<<*it3<<" ";
        ++it3;
    }
    v1.assign(first, end);//将v1清空后为v1赋值，将[first, end)区间里包含的元素赋值给v1
    v1.assign(7, 7);//将v1清空后为v1赋值7个7
    cout<<endl;
    cout<<v.at(4)<<endl;
    cout<<v[4]<<endl;
    cout<<"v.size() = "<<v.size()<<endl;//v的大小（里边有几个元素）
    cout<<"v.capacity() = "<<v.capacity()<<endl;//v的容量
    v.resize(20);//指定向量的大小为20
    cout<<"v.capacity() = "<<v.capacity()<<endl;
    return 0;
}