#pragma once

#include <iterator>

struct SequenceGenerator {

    struct iterator :
        std::iterator< std::forward_iterator_tag, int, std::ptrdiff_t, const int *, const int & >
    {
        iterator() :
            _value( 1 ),
            _sequence( 1 ),
            _limit( 0 )
        {}
        iterator( int limit ) :
            _value( 0 ),
            _sequence( 0 ),
            _limit( limit )
        {}

        int operator*() const {
            return _value;
        }

        iterator &operator++() {
            ++_value;
            ++_limit;
            if ( _value > _sequence ) {
                _value = 1;
                ++_sequence;
            }
            return *this;
        }
        iterator operator++( int ) {
            iterator self( *this );
            ++( *this );
            return self;
        }

        bool operator==( const iterator &other ) const {
            return _limit == other._limit;
        }
        bool operator!=( const iterator &other ) const {
            return !( *this == other );
        }

    private:
        int _value;
        int _sequence;
        int _limit;
    };

    SequenceGenerator( int stop ) :
        _stop( stop )
    {}

    iterator begin() const {
        return iterator();
    }
    iterator end() const {
        return iterator( _stop );
    }
private:
    int _stop;
};