#include 
     
      #include 
      
       using namespace std;int main (){    vector
       
         myints;    cout << "0. size: " << myints.size() << '\n';        for (int i=0; i<10; i++) myints.push_back(i);    cout << "1. size: " << myints.size() << '\n';        myints.insert (myints.end(),10,100);//起始位置，长度，填充元素    cout << "2. size: " << myints.size() << '\n';    for (int i=0; i<20; i++) cout << myints[i]<<" ";    myints.pop_back();    cout << "\n3. size: " << myints.size() << '\n';        return 0;}