_algo.c

MONA是为数不多的C++语言编写的一个很小的操作系统

        __first + __step_size, __last,
        __result,
        __comp);
}

const int __stl_chunk_size = 7;
        
template <class _RandomAccessIter, class _Distance, class _Compare>
void __chunk_insertion_sort(_RandomAccessIter __first, 
                            _RandomAccessIter __last,
                            _Distance __chunk_size, _Compare __comp)
{
  while (__last - __first >= __chunk_size) {
    __insertion_sort(__first, __first + __chunk_size, __comp);
    __first += __chunk_size;
  }
  __insertion_sort(__first, __last, __comp);
}

template <class _RandomAccessIter, class _Pointer, class _Distance,
          class _Compare>
void __merge_sort_with_buffer(_RandomAccessIter __first, 
                              _RandomAccessIter __last, _Pointer __buffer,
                              _Distance*, _Compare __comp) {
  _Distance __len = __last - __first;
  _Pointer __buffer_last = __buffer + __len;

  _Distance __step_size = __stl_chunk_size;
  __chunk_insertion_sort(__first, __last, __step_size, __comp);

  while (__step_size < __len) {
    __merge_sort_loop(__first, __last, __buffer, __step_size, __comp);
    __step_size *= 2;
    __merge_sort_loop(__buffer, __buffer_last, __first, __step_size, __comp);
    __step_size *= 2;
  }
}

template <class _BidirectionalIter1, class _BidirectionalIter2,
          class _Distance>
_BidirectionalIter1 __rotate_adaptive(_BidirectionalIter1 __first,
                                      _BidirectionalIter1 __middle,
                                      _BidirectionalIter1 __last,
                                      _Distance __len1, _Distance __len2,
                                      _BidirectionalIter2 __buffer,
                                      _Distance __buffer_size) {
  if (__len1 > __len2 && __len2 <= __buffer_size) {
    _BidirectionalIter2 __buffer_end = copy(__middle, __last, __buffer);
    copy_backward(__first, __middle, __last);
    return copy(__buffer, __buffer_end, __first);
  }
  else if (__len1 <= __buffer_size) {
    _BidirectionalIter2 __buffer_end = copy(__first, __middle, __buffer);
    copy(__middle, __last, __first);
    return copy_backward(__buffer, __buffer_end, __last);
  }
  else
    return rotate(__first, __middle, __last);
}

template <class _BidirectionalIter, class _Distance, class _Pointer,
          class _Compare>
void __merge_adaptive(_BidirectionalIter __first, 
                      _BidirectionalIter __middle, 
                      _BidirectionalIter __last,
                      _Distance __len1, _Distance __len2,
                      _Pointer __buffer, _Distance __buffer_size,
                      _Compare __comp) {
  if (__len1 <= __len2 && __len1 <= __buffer_size) {
    _Pointer __buffer_end = copy(__first, __middle, __buffer);
    merge(__buffer, __buffer_end, __middle, __last, __first, __comp);
  }
  else if (__len2 <= __buffer_size) {
    _Pointer __buffer_end = copy(__middle, __last, __buffer);
    __merge_backward(__first, __middle, __buffer, __buffer_end, __last,
                     __comp);
  }
  else {
    _BidirectionalIter __first_cut = __first;
    _BidirectionalIter __second_cut = __middle;
    _Distance __len11 = 0;
    _Distance __len22 = 0;
    if (__len1 > __len2) {
      __len11 = __len1 / 2;
      advance(__first_cut, __len11);
      __second_cut = lower_bound(__middle, __last, *__first_cut, __comp);
      __len22 += distance(__middle, __second_cut);   
    }
    else {
      __len22 = __len2 / 2;
      advance(__second_cut, __len22);
      __first_cut = upper_bound(__first, __middle, *__second_cut, __comp);
      __len11 += distance(__first, __first_cut);
    }
    _BidirectionalIter __new_middle =
      __rotate_adaptive(__first_cut, __middle, __second_cut, __len1 - __len11,
                        __len22, __buffer, __buffer_size);
    __merge_adaptive(__first, __first_cut, __new_middle, __len11,
                     __len22, __buffer, __buffer_size, __comp);
    __merge_adaptive(__new_middle, __second_cut, __last, __len1 - __len11,
                     __len2 - __len22, __buffer, __buffer_size, __comp);
  }
}

template <class _RandomAccessIter, class _Pointer, class _Distance, 
          class _Compare>
void __stable_sort_adaptive(_RandomAccessIter __first, 
                            _RandomAccessIter __last, _Pointer __buffer,
                            _Distance __buffer_size, _Compare __comp) {
  _Distance __len = (__last - __first + 1) / 2;
  _RandomAccessIter __middle = __first + __len;
  if (__len > __buffer_size) {
    __stable_sort_adaptive(__first, __middle, __buffer, __buffer_size, 
                           __comp);
    __stable_sort_adaptive(__middle, __last, __buffer, __buffer_size, 
                           __comp);
  }
  else {
    __merge_sort_with_buffer(__first, __middle, __buffer, (_Distance*)0,
                               __comp);
    __merge_sort_with_buffer(__middle, __last, __buffer, (_Distance*)0,
                               __comp);
  }
  __merge_adaptive(__first, __middle, __last, _Distance(__middle - __first), 
                   _Distance(__last - __middle), __buffer, __buffer_size,
                   __comp);
}

template <class _RandomAccessIter, class _Tp, class _Distance, class _Compare>
void __stable_sort_aux(_RandomAccessIter __first,
			      _RandomAccessIter __last, _Tp*, _Distance*,
			      _Compare __comp) {
  _Temporary_buffer<_RandomAccessIter, _Tp> buf(__first, __last);
  if (buf.begin() == 0)
    __inplace_stable_sort(__first, __last, __comp);
  else 
    __stable_sort_adaptive(__first, __last, buf.begin(),
                           _Distance(buf.size()),
                           __comp);
}

template <class _RandomAccessIter>
void stable_sort(_RandomAccessIter __first,
		 _RandomAccessIter __last) {
  _STLP_DEBUG_CHECK(__check_range(__first, __last))
  __stable_sort_aux(__first, __last,
                    _STLP_VALUE_TYPE(__first, _RandomAccessIter),
                    _STLP_DISTANCE_TYPE(__first, _RandomAccessIter),
                    __less(_STLP_VALUE_TYPE(__first, _RandomAccessIter)));
}

template <class _RandomAccessIter, class _Compare>
void stable_sort(_RandomAccessIter __first,
		 _RandomAccessIter __last, _Compare __comp) {
  _STLP_DEBUG_CHECK(__check_range(__first, __last))
  __stable_sort_aux(__first, __last,
                    _STLP_VALUE_TYPE(__first, _RandomAccessIter),
                    _STLP_DISTANCE_TYPE(__first, _RandomAccessIter), 
                    __comp);
}

// partial_sort, partial_sort_copy, and auxiliary functions.

template <class _RandomAccessIter, class _Tp, class _Compare>
void __partial_sort(_RandomAccessIter __first, _RandomAccessIter __middle,
                    _RandomAccessIter __last, _Tp*, _Compare __comp) {
  make_heap(__first, __middle, __comp);
  for (_RandomAccessIter __i = __middle; __i < __last; ++__i)
    if (__comp(*__i, *__first))
      __pop_heap(__first, __middle, __i, _Tp(*__i), __comp,
                 _STLP_DISTANCE_TYPE(__first, _RandomAccessIter));
  sort_heap(__first, __middle, __comp);
}


template <class _RandomAccessIter>
void 
partial_sort(_RandomAccessIter __first,_RandomAccessIter __middle, _RandomAccessIter __last) {
  _STLP_DEBUG_CHECK(__check_range(__first, __middle))
  _STLP_DEBUG_CHECK(__check_range(__middle, __last))
  __partial_sort(__first, __middle, __last, _STLP_VALUE_TYPE(__first, _RandomAccessIter), 
                 __less(_STLP_VALUE_TYPE(__first, _RandomAccessIter)));
}

template <class _RandomAccessIter, class _Compare>
void partial_sort(_RandomAccessIter __first,_RandomAccessIter __middle,
                  _RandomAccessIter __last, _Compare __comp) {
  _STLP_DEBUG_CHECK(__check_range(__first, __middle))
  _STLP_DEBUG_CHECK(__check_range(__middle, __last))
  __partial_sort(__first, __middle, __last, _STLP_VALUE_TYPE(__first, _RandomAccessIter), __comp);
}

template <class _InputIter, class _RandomAccessIter, class _Compare,
          class _Distance, class _Tp>
_RandomAccessIter __partial_sort_copy(_InputIter __first,
                                         _InputIter __last,
                                         _RandomAccessIter __result_first,
                                         _RandomAccessIter __result_last,
                                         _Compare __comp, _Distance*, _Tp*) {
  if (__result_first == __result_last) return __result_last;
  _RandomAccessIter __result_real_last = __result_first;
  while(__first != __last && __result_real_last != __result_last) {
    *__result_real_last = *__first;
    ++__result_real_last;
    ++__first;
  }
  make_heap(__result_first, __result_real_last, __comp);
  while (__first != __last) {
    if (__comp(*__first, *__result_first))
      __adjust_heap(__result_first, _Distance(0),
                    _Distance(__result_real_last - __result_first),
                    _Tp(*__first),
                    __comp);
    ++__first;
  }
  sort_heap(__result_first, __result_real_last, __comp);
  return __result_real_last;
}

template <class _InputIter, class _RandomAccessIter>
_RandomAccessIter
partial_sort_copy(_InputIter __first, _InputIter __last,
                  _RandomAccessIter __result_first, _RandomAccessIter __result_last) {
  _STLP_DEBUG_CHECK(__check_range(__first, __last))
  _STLP_DEBUG_CHECK(__check_range(__result_first, __result_last))
  return __partial_sort_copy(__first, __last, __result_first, __result_last, 
                             __less(_STLP_VALUE_TYPE(__first, _InputIter)),
                             _STLP_DISTANCE_TYPE(__result_first, _RandomAccessIter),
                             _STLP_VALUE_TYPE(__first, _InputIter));
}

template <class _InputIter, class _RandomAccessIter, class _Compare>
_RandomAccessIter
partial_sort_copy(_InputIter __first, _InputIter __last,
                  _RandomAccessIter __result_first,
                  _RandomAccessIter __result_last, _Compare __comp) {
  _STLP_DEBUG_CHECK(__check_range(__first, __last))
  _STLP_DEBUG_CHECK(__check_range(__result_first, __result_last))
  return __partial_sort_copy(__first, __last, __result_first, __result_last,
                             __comp,
                             _STLP_DISTANCE_TYPE(__result_first, _RandomAccessIter),
                             _STLP_VALUE_TYPE(__first, _InputIter));
}

// nth_element() and its auxiliary functions.  

template <class _RandomAccessIter, class _Tp, class _Compare>
void __nth_element(_RandomAccessIter __first, _RandomAccessIter __nth,
                   _RandomAccessIter __last, _Tp*, _Compare __comp) {
  while (__last - __first > 3) {
    _RandomAccessIter __cut =
      __unguarded_partition(__first, __last,
                            _Tp(__median(*__first,
                                         *(__first + (__last - __first)/2), 
                                         *(__last - 1),
                                         __comp)),
                            __comp);
    if (__cut <= __nth)
      __first = __cut;
    else 
      __last = __cut;
  }
  __insertion_sort(__first, __last, __comp);
}


template <class _RandomAccessIter>
void nth_element(_RandomAccessIter __first, _RandomAccessIter __nth,
                 _RandomAccessIter __last) {
  _STLP_DEBUG_CHECK(__check_range(__first, __nth))
  _STLP_DEBUG_CHECK(__check_range(__nth, __last))
  __nth_element(__first, __nth, __last, _STLP_VALUE_TYPE(__first, _RandomAccessIter), 
                __less(_STLP_VALUE_TYPE(__first, _RandomAccessIter)));
}

template <class _RandomAccessIter, class _Compare>
void nth_element(_RandomAccessIter __first, _RandomAccessIter __nth,
                 _RandomAccessIter __last, _Compare __comp) {
  _STLP_DEBUG_CHECK(__check_range(__first, __nth))
  _STLP_DEBUG_CHECK(__check_range(__nth, __last))
  __nth_element(__first, __nth, __last, _STLP_VALUE_TYPE(__first, _RandomAccessIter), __comp);
}

// Binary search (lower_bound, upper_bound, equal_range, binary_search).

template <class _ForwardIter, class _Tp, class _Compare, class _Distance>
_ForwardIter __upper_bound(_ForwardIter __first, _ForwardIter __last,
                           const _Tp& __val, _Compare __comp, _Distance*)
{
  _Distance __len = distance(__first, __last);
  _Distance __half;

  while (__len > 0) {
    __half = __len >> 1;
    _ForwardIter __middle = __first;
    advance(__middle, __half);
    if (__comp(__val, *__middle))
      __len = __half;
    else {
      __first = __middle;
      ++__first;
      __len = __len - __half - 1;
    }
  }
  return __first;
}

template <class _ForwardIter, class _Tp, class _Compare, class _Distance>
pair<_ForwardIter, _ForwardIter>
__equal_range(_ForwardIter __first, _ForwardIter __last, const _Tp& __val,
              _Compare __comp, _Distance*)
{
  _Distance __len = distance(__first, __last);
  _Distance __half;

  while (__len > 0) {
    __half = __len >> 1;
    _ForwardIter __middle = __first;
    advance(__middle, __half);
    if (__comp(*__middle, __val)) {
      __first = __middle;
      ++__first;
      __len = __len - __half - 1;
    }
    else if (__comp(__val, *__middle))
      __len = __half;
    else {
      _ForwardIter __left = lower_bound(__first, __middle, __val, __comp);
      advance(__first, __len);
      _ForwardIter __right = upper_bound(++__middle, __first, __val, __comp);
      return pair<_ForwardIter, _ForwardIter>(__left, __right);
    }
  }
  return pair<_ForwardIter, _ForwardIter>(__first, __first);
}           

template <class _InputIter1, class _InputIter2, class _OutputIter>
_OutputIter merge(_InputIter1 __first1, _InputIter1 __last1,
                  _InputIter2 __first2, _InputIter2 __last2,
                  _OutputIter __result) {
  _STLP_DEBUG_CHECK(__check_range(__first1, __last1))
  _STLP_DEBUG_CHECK(__check_range(__first2, __last2))
  while (__first1 != __last1 && __first2 != __last2) {
    if (*__first2 < *__first1) {
      *__result = *__first2;
      ++__first2;
    }
    else {
      *__result = *__first1;
      ++__first1;
    }
    ++__result;
  }
  return copy(__first2, __last2, copy(__first1, __last1, __result));
}

template <class _InputIter1, class _InputIter2, class _OutputIter,
          class _Compare>
_OutputIter merge(_InputIter1 __first1, _InputIter1 __last1,
                  _InputIter2 __first2, _InputIter2 __last2,
                  _OutputIter __result, _Compare __comp) {
  _STLP_DEBUG_CHECK(__check_range(__first1, __last1))
  _STLP_DEBUG_CHECK(__check_range(__first2, __last2))
  while (__first1 != __last1 && __first2 != __last2) {
    if (__comp(*__first2, *__first1)) {
      *__result = *__first2;
      ++__first2;
    }
    else {
      *__result = *__first1;
      ++__first1;
    }
    ++__result;
  }
  return copy(__first2, __last2, copy(__first1, __last1, __result));
}

template <class _BidirectionalIter, class _Distance, class _Compare>
void __merge_without_buffer(_BidirectionalIter __first,
                            _BidirectionalIter __middle,
                            _BidirectionalIter __last,
                            _Distance __len1, _Distance __len2,
                            _Compare __comp) {
  if (__len1 == 0 || __len2 == 0)
    return;
  if (__len1 + __len2 == 2) {
    if (__comp(*__middle, *__first))
      iter_swap(__first, __middle);
    return;
  }
  _BidirectionalIter __first_cut = __first;
  _BidirectionalIter __second_cut = __middle;
  _Distance __len11 = 0;
  _Distance __len22 = 0;
  if (__len1 > __len2) {
    __len11 = __len1 / 2;
    advance(__first_cut, __len11);
    __second_cut = lower_bound(__middle, __last, *__first_cut, __comp);
    __len22 += distance(__middle, __second_cut);
  }
  else {
    __len22 = __len2 / 2;
    advance(__second_cut, __len22);
    __first_cut = upper_bound(__first, __middle, *__second_cut, __comp);
    __len11 +=distance(__first, __first_cut);
  }
  _BidirectionalIter __new_middle
    = rotate(__first_cut, __middle, __second_cut);
  __merge_without_buffer(__first, __first_cut, __new_middle, __len11, __len22,
                         __comp);
  __merge_without_buffer(__new_middle, __second_cut, __last, __len1 - __len11,
                         __len2 - __len22, __comp);
}

template <class _BidirectionalIter1, class _BidirectionalIter2,
          class _BidirectionalIter3, class _Compare>
_BidirectionalIter3 __merge_backward(_BidirectionalIter1 __first1,
                                     _BidirectionalIter1 __last1,
                                     _BidirectionalIter2 __first2,
                                     _BidirectionalIter2 __last2,
                                     _BidirectionalIter3 __result,
                                     _Compare __comp) {
  if (__first1 == __last1)
    return copy_backward(__first2, __last2, __result);
  if (__first2 == __last2)
    return copy_backward(__first1, __last1, __result);
  --__last1;
  --__last2;
  while (true) {
    if (__comp(*__last2, *__last1)) {
      *--__result = *__last1;
      if (__first1 == __last1)
        return copy_backward(__first2, ++__last2, __result);
      --__last1;
    }
    else {
      *--__result = *__last2;
      if (__first2 == __last2)
        return copy_backward(__first1, ++__last1, __result);
      --__last2;
    }
  }