// test vector class
//
#include <vector>
#include <iostream>

using namespace std;

int main( void)
{
 // initialize vector from an array
 // int a[] = { 1, 2, 3};  cout << "a = "; for( int x : a) { cout << " " << x; }  cout << endl;
 // vector<int> v( a, a+3);

 // initializer list, see https://en.cppreference.com/w/cpp/language/list_initialization
 //
  vector<int> v { 1, 2, 3};

 // print using range-based for loop
 //
  cout << "v = "; for( int x : v) { cout << " " << x; }  cout << endl;

  cout << "v = "; for( const auto& x : v) { cout << " " << x; }  cout << endl;

 // print using v.at() indexing
 //
  cout << "v = "; for( size_t i = 0; i < v.size(); ++i)
		  { cout << " " << v.at(i); }  cout << endl;

 // print using iterator (it is something like a pointer to int)
 //
  cout << "v = "; for( vector<int>::const_iterator it = v.begin(); it != v.end(); ++it)
		  { cout << " " << *it; }  cout << endl;

 // append another element
 //
  v.push_back(4); 

  cout << "v = "; for( int x : v) { cout << " " << x; }  cout << endl;

 // erase v[1] and v[2]
 //
  vector<int>::iterator it = v.begin() + 1; // points to v.at(1)

  v.erase( it, it+2); 

  cout << "v = "; for( int x : v) { cout << " " << x; }  cout << endl;
}