stl vector

初始化 

vector<int> chars(26, 0);    // initialized as 26 zeros

int myints[] = {10,20,30,5,15};
std::vector<int> v(myints,myints+5);

insert

b.insert(b.end(), a.begin(), a.end())

at

Access element (public member function )

front

Access first element (public member function )

clear  　　

清空元素，但不回收空间

back

Access last element (public member function )

push_back

Add element at the end (public member function )

pop_back

　　Delete last element (public member function )

 

关于capacity 和 reserve：

vector<int> a;
    cout<<a.capacity()<<endl;  // 0
    
    a.push_back(1);
    cout<<a.capacity()<<endl;  // 1
    
    a.push_back(1);
    cout<<a.capacity()<<endl;  // 2
    
    a.push_back(1);
    cout<<a.capacity()<<endl;  // 4
    
    a.push_back(1);
    cout<<a.capacity()<<endl;  // 4
    
    a.push_back(1);
    cout<<a.capacity()<<endl;   // 8
    
    a.reserve(33);
    cout<<a.capacity()<<endl;   // 33
    
    a.reserve(15);
    cout<<a.capacity()<<endl;   // 33