gistfile1.cpp

#include <iostream>

#include <stddef.h>

namespace mozilla {

template<typename Iterator>
struct IteratorTraits
{
  typedef typename Iterator::ValueType ValueType;
};

template<typename T>
struct IteratorTraits<T*>
{
  typedef T ValueType;
};

template<typename T>
struct IteratorTraits<const T*>
{
  typedef const T ValueType;
};

} // namespace mozilla

namespace mozilla {

template<typename IteratorT>
class ReverseIterator
{
public:
  typedef typename IteratorTraits<IteratorT>::ValueType ValueType;

  template<typename Iterator>
  explicit ReverseIterator(Iterator aIter)
    : mCurrent(aIter) { }

  template<typename Iterator>
  ReverseIterator(const ReverseIterator<Iterator>& aOther)
    : mCurrent(aOther.mCurrent) { }

  ValueType& operator*() const
  {
    IteratorT tmp = mCurrent;
    return *--tmp;
  }

  /* Increments and decrements operators */

  ReverseIterator& operator++() { --mCurrent; return *this; }
  ReverseIterator& operator--() { ++mCurrent; return *this; }
  ReverseIterator operator++(int) { auto ret = *this; mCurrent--; return ret; }
  ReverseIterator operator--(int) { auto ret = *this; mCurrent++; return ret; }

  /* Comparison operators */

  template<typename Iterator1, typename Iterator2>
  friend bool operator==(const ReverseIterator<Iterator1>& aIter1,
                         const ReverseIterator<Iterator2>& aIter2);
  template<typename Iterator1, typename Iterator2>
  friend bool operator!=(const ReverseIterator<Iterator1>& aIter1,
                         const ReverseIterator<Iterator2>& aIter2);

private:
  IteratorT mCurrent;
};

template<typename Iterator1, typename Iterator2>
bool
operator==(const ReverseIterator<Iterator1>& aIter1,
           const ReverseIterator<Iterator2>& aIter2)
{
  return aIter1.mCurrent == aIter2.mCurrent;
}

template<typename Iterator1, typename Iterator2>
bool
operator!=(const ReverseIterator<Iterator1>& aIter1,
           const ReverseIterator<Iterator2>& aIter2)
{
  return aIter1.mCurrent != aIter2.mCurrent;
}

namespace detail {

template<typename IteratorT>
class IteratorRange
{
public:
  typedef IteratorT iterator;
  typedef IteratorT const_iterator;
  typedef ReverseIterator<IteratorT> reverse_iterator;
  typedef ReverseIterator<IteratorT> const_reverse_iterator;

  template<typename Iterator1, typename Iterator2>
  IteratorRange(Iterator1 aIterBegin, Iterator2 aIterEnd)
    : mIterBegin(aIterBegin), mIterEnd(aIterEnd) { }

  template<typename Iterator>
  IteratorRange(const IteratorRange<Iterator>& aOther)
    : mIterBegin(aOther.mIterBegin), mIterEnd(aOther.mIterEnd) { }

  iterator begin() const { return mIterBegin; }
  const_iterator cbegin() const { return begin(); }
  iterator end() const { return mIterEnd; }
  const_iterator cend() const { return end(); }
  reverse_iterator rbegin() const { return reverse_iterator(mIterEnd); }
  const_reverse_iterator crbegin() const { return rbegin(); }
  reverse_iterator rend() const { return reverse_iterator(mIterBegin); }
  const_reverse_iterator crend() const { return rend(); }

private:
  IteratorT mIterBegin;
  IteratorT mIterEnd;
};

} // namespace detail

template<typename Range>
detail::IteratorRange<typename Range::reverse_iterator>
Reversed(Range& aRange)
{
  return {aRange.rbegin(), aRange.rend()};
}

template<typename Range>
detail::IteratorRange<typename Range::const_reverse_iterator>
Reversed(const Range& aRange)
{
  return {aRange.rbegin(), aRange.rend()};
}

} // namespace mozilla

namespace mozilla {

namespace detail {

template<typename IntTypeT>
class IntegerIterator
{
public:
  typedef const IntTypeT ValueType;

  template<typename IntType>
  explicit IntegerIterator(IntType aCurrent)
    : mCurrent(aCurrent) { }

  template<typename IntType>
  IntegerIterator(const IntegerIterator<IntType>& aOther)
    : mCurrent(aOther.mCurrent) { }

  // Since operator* is required to return a reference, we return
  // a reference to our member here.
  const IntTypeT& operator*() const { return mCurrent; }

  /* Increment and decrement operators */

  IntegerIterator& operator++() { ++mCurrent; return *this; }
  IntegerIterator& operator--() { --mCurrent; return *this; }
  IntegerIterator operator++(int) { auto ret = *this; ++mCurrent; return ret; }
  IntegerIterator operator--(int) { auto ret = *this; --mCurrent; return ret; }

  /* Comparison operators */

  template<typename IntType1, typename IntType2>
  friend bool operator==(const IntegerIterator<IntType1>& aIter1,
                         const IntegerIterator<IntType2>& aIter2);
  template<typename IntType1, typename IntType2>
  friend bool operator!=(const IntegerIterator<IntType1>& aIter1,
                         const IntegerIterator<IntType2>& aIter2);

private:
  IntTypeT mCurrent;
};

template<typename IntType1, typename IntType2>
bool operator==(const IntegerIterator<IntType1>& aIter1,
                const IntegerIterator<IntType2>& aIter2)
{
  return aIter1.mCurrent == aIter2.mCurrent;
}

template<typename IntType1, typename IntType2>
bool operator!=(const IntegerIterator<IntType1>& aIter1,
                const IntegerIterator<IntType2>& aIter2)
{
  return aIter1.mCurrent != aIter2.mCurrent;
}

template<typename IntTypeT>
class IntegerRange
{
public:
  typedef IntegerIterator<IntTypeT> iterator;
  typedef IntegerIterator<IntTypeT> const_iterator;
  typedef ReverseIterator<IntegerIterator<IntTypeT>> reverse_iterator;
  typedef ReverseIterator<IntegerIterator<IntTypeT>> const_reverse_iterator;

  template<typename IntType>
  explicit IntegerRange(IntType aEnd)
    : mBegin(0), mEnd(aEnd) { }

  template<typename IntType1, typename IntType2>
  IntegerRange(IntType1 aBegin, IntType2 aEnd)
    : mBegin(aBegin), mEnd(aEnd) { }

  iterator begin() const { return iterator(mBegin); }
  const_iterator cbegin() const { return begin(); }
  iterator end() const { return iterator(mEnd); }
  const_iterator cend() const { return end(); }
  reverse_iterator rbegin() const { return reverse_iterator(mEnd); }
  const_reverse_iterator crbegin() const { return rbegin(); }
  reverse_iterator rend() const { return reverse_iterator(mBegin); }
  const_reverse_iterator crend() const { return rend(); }

private:
  IntTypeT mBegin;
  IntTypeT mEnd;
};

} // namespace detail

template<typename IntType>
detail::IntegerRange<IntType>
MakeRange(IntType aEnd)
{
  return detail::IntegerRange<IntType>(aEnd);
}

template<typename IntType1, typename IntType2>
detail::IntegerRange<IntType2>
MakeRange(IntType1 aBegin, IntType2 aEnd)
{
  return detail::IntegerRange<IntType2>(aBegin, aEnd);
}

} // namespace mozilla

using namespace mozilla;

int main()
{
  size_t n;
  std::cin >> n;

  for (auto i : Reversed(MakeRange(n))) {
    std::cout << i << std::endl;
  }
}