#include <string>
#include <iostream>

using namespace std;

template <typename T>
  class Vector
{
protected:
  T * data;
  int size, num;

  void enlarge()
  { int newsize = size * 2;
    if (newsize == 0)
      newsize = 1;
    T * news = new T [newsize];
    for (int i = 0; i < num; i += 1)
      news[i] = data[i];
    delete [] data;
    data = news;
    size = newsize; }

public:
  Vector(int initsize)
  { size = initsize;
    num = 0;
    data = new T[size]; }

  T & get(int i)
  { if (i < 0 || i >= num)
    { cout << "index out of bounds\n";
      abort(); }
    return data[i]; }

  int get_num()
  { return num; }

  void push_back(T s)
  { if (num >= size)
      enlarge();
    data[num] = s;
    num += 1; }
};

int main()
{ Vector<string> v(2);
  v.push_back("ant");
  v.push_back("bat");
  v.push_back("cat");
  v.push_back("dog");
  v.push_back("emu");
  v.push_back("fly");
  v.push_back("gnu");
  v.push_back("hen");
  Vector<int> w(2);
  w.push_back(3);
  w.push_back(1);
  w.push_back(4);
  w.push_back(1);
  w.push_back(5);
  w.push_back(9);
  w.push_back(2);
  for (int i = 0; i < v.get_num(); i += 1)
  { cout << i << ": " << v.get(i) << "\n"; }

  v.get(5) = "hippopotamus";  

  for (int i = 0; i < v.get_num(); i += 1)
  { cout << i << ": " << v.get(i) << "\n"; }
  for (int i = 0; i < w.get_num(); i += 1)
  { cout << i << ": " << w.get(i) << "\n"; } }