#include <iostream>
#include<vector>
using namespace std;
int main()
{
    vector<int> v={12,13,14,15};
    cout<<"initial vector:"<<endl;
    for(int i:v)
    cout<<i<<endl;
    v.push_back(100);
    v.push_back(200);
    cout<<"after adding two element,contents of vector are:\n";
    for(int i:v)
    cout<<i<<endl;
    cout<<"elements at index 1:"<<v.at(1)<<endl;
    cout<<"elements at index 3:"<<v.at(3)<<endl;
    v.at(4)=700;
    cout<<"after updateing the contents of vector:"<<endl;
    for(int i:v)
    cout<<i<<endl;
    
    v.pop_back();
    v.pop_back();
    cout<<"after deleting an element contents of vector are:"<<endl;
    for (int i:v)
    cout<<i<<endl;
    cout<<v.empty();
    if(v.empty()==0)
    cout<<" vector is not empty";
    else
    cout<<"vector is empty"<<endl;

    cout<<v.size()<<endl;
    v.clear();
    cout<<v.size();
    for(int i:v)
    cout<<i<<endl;
    return 0;
}