#include "test_runner.h"

#include <numeric>
#include <iostream>
#include <vector>
#include <string>
using namespace std;


template<typename Iterator>
class IteratorRange {
private:
    Iterator first, last;
public:
    IteratorRange(Iterator f, Iterator l) :
            first(f), last(l) {
    }
    Iterator begin() const {
        return first;
    }
    Iterator end() const {
        return last;
    }
    size_t size() const{
        return last - first;
    }
};

template <typename Iterator>
class Paginator {
private:
    vector<IteratorRange<Iterator>> vector_it;
    Iterator first;
    Iterator last;
    size_t page_size;
public:
    Paginator(Iterator f, Iterator l, size_t page_size_) :
        first(f), last(l), page_size(page_size_) {
        while(first != last) {
            auto pr = first;
            for (size_t i = 0; i < page_size; ++i) {
                first++;
                if (first == last) {
                    break;
                }
            }
            vector_it.push_back({pr, first});
        }
    }
    Iterator begin() const {
        return vector_it.begin();
    }
    Iterator end() const {
        return vector_it.end();
    }
    size_t size() const{
        return vector_it.size();
    }

};

template <typename C>
auto Paginate(C& c, size_t page_size) {
  return Paginator{c.begin(), c.end(), page_size};
}