#include <memory>
#include <vector>
#include <iostream>

using namespace std;

template<typename T> class Pole {
public:
	class iterator;

	Pole(size_t chunk = 100) : chunk_(chunk), size_(0) {}
	void push_back(const T& x) { resize(++size_); (*this)[size_ - 1] = x; }
	T& operator[] (size_t i) { return hrabe_[i / chunk_][i%chunk_]; }
	T& at(size_t i) { check(i); return (*this)[i]; }

	iterator begin() { return iterator(*this, 0); }
	iterator end() { return iterator(*this, size_); }
private:
	void check(size_t i) { if (i >= size_)  throw out_of_range("Out of range"); }
	void resize(size_t i) {
		for (size_t k = hrabe_.size(); k <= i / chunk_; ++k)
			hrabe_.push_back(make_unique< T[]>(chunk_));
	}
	size_t chunk_;
	size_t size_;
	vector< unique_ptr<T[]>> hrabe_;
};

template <typename T>
class Pole<T>::iterator {
public:
	iterator(Pole<T>& pole, size_t i) : pole_(pole), i_(i) {}
	T& operator*() { return pole_[i_]; }
	bool operator!=(const iterator& other) { return i_ != other.i_; }
	iterator& operator++() { i_++; return *this; }
	iterator& operator++(int) { iterator it(*this); (*this)++; return it; }
private:
	size_t i_;
	Pole<T>& pole_;
};

int main() {
	Pole<int> p;
	p.push_back(42);
	p.push_back(43);
	p.push_back(44);

	cout << p[0] << ' ' << p.at(1) << ' ' << p.at(2) << endl;

	for (Pole<int>::iterator it = p.begin(); it != p.end(); ++it) {
		cout << *it << ' ';
	}
	cout << endl;

	for (auto n : p) {
		cout << n << ' ';
	}

	return 0;
}