vector example in c++

#include<iostream>
#include<conio.h>

#include<vector>
using namespace std;
int  main( )
{
vector<int> v;
 v.assign( 10, 42 );
 for( int i = 0; i < v.size(); i++ ) {
     v.push_back(i);
   cout << v[i] << " " << endl;

 
 }
     cout <<"first element is :"<< v.front();
      cout <<"last element is :"<< v.back();
    
 cout << endl;   
    getch();
    return 0;                                                      
}