///////////////////////////////////////////
//  vector.cpp -- how do I use a vector? //
///////////////////////////////////////////
#include <vector>
#include <iostream>
using namespace std;

void main() {

  vector<double> v;

  v.push_back(0.50);          // push-back operation will silently
  v.push_back(0.75);          // allocate memory as needed to hold the
  v.push_back(1.00);          // push_back entries
  v.push_back(1.25);

  cout << "\n  the vector length is " << v.size() << "\n\n"
       << "  it contains the elements ";

  int i;
  for(i=0; i<v.size(); i++)
    cout << v[i] << "  ";     // indexing is only defined over the size
  cout << "\n\n";             // of the array after entries are made

  cout << "  changing the 2nd element to 2.00:\n\n";

  v[1] = 2.00;

  cout << "  its elements are now ";
  for(i=0; i<v.size(); i++)
    cout << v[i] << "  ";
  cout << "\n\n";

}