/*

 *

 * Copyright (c) 1994

 * Hewlett-Packard Company

 *

 * Copyright (c) 1996,1997

 * Silicon Graphics Computer Systems, Inc.

 *

 * Copyright (c) 1997

 * Moscow Center for SPARC Technology

 *

 * Copyright (c) 1999 

 * Boris Fomitchev

 *

 * This material is provided "as is", with absolutely no warranty expressed

 * or implied. Any use is at your own risk.

 *

 * Permission to use or copy this software for any purpose is hereby granted 

 * without fee, provided the above notices are retained on all copies.

 * Permission to modify the code and to distribute modified code is granted,

 * provided the above notices are retained, and a notice that the code was

 * modified is included with the above copyright notice.

 *

 */

#ifndef _STLP_ALGO_C

# define _STLP_ALGO_C

# if !defined (_STLP_INTERNAL_ALGO_H)

#  include <stl/_algo.h>

# endif

_STLP_BEGIN_NAMESPACE

template <class _BidirectionalIter, class _Distance, class _Compare>

void __merge_without_buffer(_BidirectionalIter __first,

                            _BidirectionalIter __middle,

                            _BidirectionalIter __last,

                            _Distance __len1, _Distance __len2,

                            _Compare __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);

template <class _Tp>

# if !(defined (__SUNPRO_CC) && (__SUNPRO_CC < 0x420 ))

inline 

# endif

const _Tp& __median(const _Tp& __a, const _Tp& __b, const _Tp& __c) {

  if (__a < __b)

    if (__b < __c)

      return __b;

    else if (__a < __c)

      return __c;

    else

      return __a;

  else if (__a < __c)

    return __a;

  else if (__b < __c)

    return __c;

  else

    return __b;

}

template <class _Tp, class _Compare>

# if !(defined (__SUNPRO_CC) && (__SUNPRO_CC < 0x420 ))

inline 

# endif

const _Tp&

__median(const _Tp& __a, const _Tp& __b, const _Tp& __c, _Compare __comp) {

  if (__comp(__a, __b))

    if (__comp(__b, __c))

      return __b;

    else if (__comp(__a, __c))

      return __c;

    else

      return __a;

  else if (__comp(__a, __c))

    return __a;

  else if (__comp(__b, __c))

    return __c;

  else

    return __b;

}

template <class _ForwardIter1, class _ForwardIter2>

_ForwardIter1 search(_ForwardIter1 __first1, _ForwardIter1 __last1,

                     _ForwardIter2 __first2, _ForwardIter2 __last2) 

{

  _STLP_DEBUG_CHECK(__check_range(__first1, __last1))

  _STLP_DEBUG_CHECK(__check_range(__first2, __last2))

  // Test for empty ranges

  if (__first1 == __last1 || __first2 == __last2)

    return __first1;

  // Test for a pattern of length 1.

  _ForwardIter2 __tmp(__first2);

  ++__tmp;

  if (__tmp == __last2)

    return find(__first1, __last1, *__first2);

  // General case.

  _ForwardIter2 __p1 = __first2; 

  ++__p1;

  _ForwardIter1 __current = __first1;

  while (__first1 != __last1) {

    __first1 = find(__first1, __last1, *__first2);

    if (__first1 == __last1)

      return __last1;

    _ForwardIter2 __p = __p1;

    __current = __first1; 

    if (++__current == __last1)

      return __last1;

    while (*__current == *__p) {

      if (++__p == __last2)

        return __first1;

      if (++__current == __last1)

        return __last1;

    }

    ++__first1;

  }

  return __first1;

}

// search_n.  Search for __count consecutive copies of __val.

template <class _ForwardIter, class _Integer, class _Tp>

_ForwardIter search_n(_ForwardIter __first, _ForwardIter __last,

                      _Integer __count, const _Tp& __val) {

  _STLP_DEBUG_CHECK(__check_range(__first, __last))

  if (__count <= 0)

    return __first;

  else {

    __first = find(__first, __last, __val);

    while (__first != __last) {

      _Integer __n = __count - 1;

      _ForwardIter __i = __first;

      ++__i;

      while (__i != __last && __n != 0 && *__i == __val) {

        ++__i;

        --__n;

      }

      if (__n == 0)

        return __first;

      else

        __first = find(__i, __last, __val);

    }

    return __last;

  }

}

template <class _ForwardIter, class _Integer, class _Tp, class _BinaryPred>

_ForwardIter search_n(_ForwardIter __first, _ForwardIter __last,

                      _Integer __count, const _Tp& __val,

                      _BinaryPred __binary_pred) {

  _STLP_DEBUG_CHECK(__check_range(__first, __last))

  if (__count <= 0)

    return __first;

  else {

    while (__first != __last) {

      if (__binary_pred(*__first, __val))

        break;

      ++__first;

    }

    while (__first != __last) {

      _Integer __n = __count - 1;

      _ForwardIter __i = __first;

      ++__i;

      while (__i != __last && __n != 0 && __binary_pred(*__i, __val)) {

        ++__i;

        --__n;

      }

      if (__n == 0)

        return __first;

      else {

        while (__i != __last) {

          if (__binary_pred(*__i, __val))

            break;

          ++__i;

        }

        __first = __i;

      }

    }

    return __last;

  }

} 

template <class _ForwardIter1, class _ForwardIter2>

_ForwardIter1 

find_end(_ForwardIter1 __first1, _ForwardIter1 __last1, 

         _ForwardIter2 __first2, _ForwardIter2 __last2)

{

  _STLP_DEBUG_CHECK(__check_range(__first1, __last1))

  _STLP_DEBUG_CHECK(__check_range(__first2, __last2))

  return __find_end(__first1, __last1, __first2, __last2,

# if defined (_STLP_CLASS_PARTIAL_SPECIALIZATION)

                    _STLP_ITERATOR_CATEGORY(__first1, _ForwardIter1),

                    _STLP_ITERATOR_CATEGORY(__first2, _ForwardIter2),

# else

		    forward_iterator_tag(),

                    forward_iterator_tag(),

# endif

                    __equal_to(_STLP_VALUE_TYPE(__first1, _ForwardIter1))

    );

}

// unique and unique_copy

template <class _InputIterator, class _OutputIterator, class _BinaryPredicate,

					    class _Tp>

_STLP_INLINE_LOOP _OutputIterator 

__unique_copy(_InputIterator __first, _InputIterator __last,

              _OutputIterator __result,

              _BinaryPredicate __binary_pred, _Tp*) {

  _Tp __val = *__first;

 _STLP_PUSH_STACK_ITEM(_Tp, &__val)

  *__result = __val;

  while (++__first != __last)

    if (!__binary_pred(__val, *__first)) {

      __val = *__first;

      *++__result = __val;

    }

  return ++__result;

}

template <class _InputIter, class _OutputIter, class _BinaryPredicate>

inline _OutputIter 

__unique_copy(_InputIter __first, _InputIter __last,_OutputIter __result,

              _BinaryPredicate __binary_pred, const output_iterator_tag &) {

  return __unique_copy(__first, __last, __result, __binary_pred, _STLP_VALUE_TYPE(__first, _InputIter));

}

template <class _InputIter, class _ForwardIter, class _BinaryPredicate>

_STLP_INLINE_LOOP _ForwardIter 

__unique_copy(_InputIter __first, _InputIter __last, _ForwardIter __result, 

              _BinaryPredicate __binary_pred, const forward_iterator_tag &) {

  *__result = *__first;

  while (++__first != __last)

    if (!__binary_pred(*__result, *__first)) *++__result = *__first;

  return ++__result;

}

# if defined (_STLP_NONTEMPL_BASE_MATCH_BUG)

template <class _InputIterator, class _BidirectionalIterator, class _BinaryPredicate>

inline _BidirectionalIterator 

__unique_copy(_InputIterator __first, _InputIterator __last,

              _BidirectionalIterator __result, _BinaryPredicate __binary_pred,

              const bidirectional_iterator_tag &) {

  return __unique_copy(__first, __last, __result, __binary_pred, forward_iterator_tag());

}

template <class _InputIterator, class _RandomAccessIterator, class _BinaryPredicate>

inline _RandomAccessIterator 

__unique_copy(_InputIterator __first, _InputIterator __last,

              _RandomAccessIterator __result, _BinaryPredicate __binary_pred,

              const random_access_iterator_tag &) {

  return __unique_copy(__first, __last, __result, __binary_pred, forward_iterator_tag());

}

# endif /* _STLP_NONTEMPL_BASE_MATCH_BUG */

template <class _InputIter, class _OutputIter>

_OutputIter 

unique_copy(_InputIter __first, _InputIter __last, _OutputIter __result) {

  _STLP_DEBUG_CHECK(__check_range(__first, __last))

  if (__first == __last) return __result;

  return __unique_copy(__first, __last, __result, __equal_to(_STLP_VALUE_TYPE(__first, _InputIter)),

                       _STLP_ITERATOR_CATEGORY(__result, _OutputIter));

}

template <class _InputIter, class _OutputIter, class _BinaryPredicate>

_OutputIter 

unique_copy(_InputIter __first, _InputIter __last,_OutputIter __result,

            _BinaryPredicate __binary_pred) {

  _STLP_DEBUG_CHECK(__check_range(__first, __last))

  if (__first == __last) return __result;

  return __unique_copy(__first, __last, __result, __binary_pred,

                       _STLP_ITERATOR_CATEGORY(__result, _OutputIter));

}

// rotate and rotate_copy, and their auxiliary functions

template <class _ForwardIter, class _Distance>

_ForwardIter __rotate(_ForwardIter __first,

                      _ForwardIter __middle,

                      _ForwardIter __last,

                      _Distance*,

                      const forward_iterator_tag &) {

  if (__first == __middle)

    return __last;

  if (__last  == __middle)

    return __first;

  _ForwardIter __first2 = __middle;

  do {

    swap(*__first++, *__first2++);

    if (__first == __middle)

      __middle = __first2;

  } while (__first2 != __last);

  _ForwardIter __new_middle = __first;

  __first2 = __middle;

  while (__first2 != __last) {

    swap (*__first++, *__first2++);

    if (__first == __middle)

      __middle = __first2;

    else if (__first2 == __last)

      __first2 = __middle;

  }

  return __new_middle;

}

template <class _BidirectionalIter, class _Distance>

_BidirectionalIter __rotate(_BidirectionalIter __first,

                            _BidirectionalIter __middle,

                            _BidirectionalIter __last,

                            _Distance*,

                            const bidirectional_iterator_tag &) {

  if (__first == __middle)

    return __last;

  if (__last  == __middle)

    return __first;

  __reverse(__first,  __middle, bidirectional_iterator_tag());

  __reverse(__middle, __last,   bidirectional_iterator_tag());

  while (__first != __middle && __middle != __last)

    swap (*__first++, *--__last);

  if (__first == __middle) {

    __reverse(__middle, __last,   bidirectional_iterator_tag());

    return __last;

  }

  else {

    __reverse(__first,  __middle, bidirectional_iterator_tag());

    return __first;

  }

}

template <class _RandomAccessIter, class _Distance, class _Tp>

_RandomAccessIter __rotate(_RandomAccessIter __first,

                           _RandomAccessIter __middle,

                           _RandomAccessIter __last,

                           _Distance *, _Tp *) {

  _Distance __n = __last   - __first;

  _Distance __k = __middle - __first;

  _Distance __l = __n - __k;

  _RandomAccessIter __result = __first + (__last - __middle);

  if (__k==0)  /* __first == middle */

    return __last;

  if (__k == __l) {

    swap_ranges(__first, __middle, __middle);

    return __result;

  }

  _Distance __d = __gcd(__n, __k);

  for (_Distance __i = 0; __i < __d; __i++) {

    _Tp __tmp = *__first;

    _STLP_PUSH_STACK_ITEM(_Tp, &__tmp)

    _RandomAccessIter __p = __first;

    if (__k < __l) {

      for (_Distance __j = 0; __j < __l/__d; __j++) {

	if (__p > __first + __l) {

          *__p = *(__p - __l);

          __p -= __l;

        }

        *__p = *(__p + __k);

        __p += __k;

      }

    }

    else {

      for (_Distance __j = 0; __j < __k/__d - 1; __j ++) {

        if (__p < __last - __k) {

          *__p = *(__p + __k);

          __p += __k;

        }

        *__p = * (__p - __l);

        __p -= __l;

      }

    }

    *__p = __tmp;

    ++__first;

  }

  return __result;

}

template <class _RandomAccessIter, class _Distance>

inline _RandomAccessIter 

__rotate(_RandomAccessIter __first, _RandomAccessIter __middle, _RandomAccessIter __last,

         _Distance * __dis, const random_access_iterator_tag &) {

  return __rotate(__first, __middle, __last,

                  __dis, _STLP_VALUE_TYPE(__first, _RandomAccessIter));

}

template <class _ForwardIter>

_ForwardIter 

rotate(_ForwardIter __first, _ForwardIter __middle, _ForwardIter __last) {

  _STLP_DEBUG_CHECK(__check_range(__first, __middle))

  _STLP_DEBUG_CHECK(__check_range(__middle, __last))

  return __rotate(__first, __middle, __last,

                  _STLP_DISTANCE_TYPE(__first, _ForwardIter),

                  _STLP_ITERATOR_CATEGORY(__first, _ForwardIter));

}

// Return a random number in the range [0, __n).  This function encapsulates

// whether we're using rand (part of the standard C library) or lrand48

// (not standard, but a much better choice whenever it's available).

template <class _Distance>

inline _Distance __random_number(_Distance __n) {

#ifdef _STLP_NO_DRAND48

  return rand() % __n;

#else

  return lrand48() % __n;

#endif

}

template <class _RandomAccessIter>

void random_shuffle(_RandomAccessIter __first,

		    _RandomAccessIter __last) {

  _STLP_DEBUG_CHECK(__check_range(__first, __last))

  if (__first == __last) return;

  for (_RandomAccessIter __i = __first + 1; __i != __last; ++__i)

    iter_swap(__i, __first + __random_number((__i - __first) + 1));

}

template <class _RandomAccessIter, class _RandomNumberGenerator>

void random_shuffle(_RandomAccessIter __first, _RandomAccessIter __last,

                    _RandomNumberGenerator& __rand) {

  _STLP_DEBUG_CHECK(__check_range(__first, __last))

  if (__first == __last) return;

  for (_RandomAccessIter __i = __first + 1; __i != __last; ++__i)

    iter_swap(__i, __first + __rand((__i - __first) + 1));

}

# ifndef _STLP_NO_EXTENSIONS

// random_sample and random_sample_n (extensions, not part of the standard).

template <class _ForwardIter, class _OutputIter, class _Distance>

_OutputIter random_sample_n(_ForwardIter __first, _ForwardIter __last,

                            _OutputIter __stl_out, const _Distance __n)

{

  _STLP_DEBUG_CHECK(__check_range(__first, __last))

  _Distance __remaining = distance(__first, __last);

  _Distance __m = (min) (__n, __remaining);

  while (__m > 0) {

    if (__random_number(__remaining) < __m) {

      *__stl_out = *__first;

      ++__stl_out;

      --__m;

    }

    --__remaining;

    ++__first;

  }

  return __stl_out;

}

template <class _ForwardIter, class _OutputIter, class _Distance,

          class _RandomNumberGenerator>

_OutputIter random_sample_n(_ForwardIter __first, _ForwardIter __last,

                            _OutputIter __stl_out, const _Distance __n,

                            _RandomNumberGenerator& __rand)

{

  _STLP_DEBUG_CHECK(__check_range(__first, __last))

  _Distance __remaining = distance(__first, __last);

  _Distance __m = (min) (__n, __remaining);

  while (__m > 0) {

    if (__rand(__remaining) < __m) {

      *__stl_out = *__first;

      ++__stl_out;

      --__m;

    }

    --__remaining;

    ++__first;

  }

  return __stl_out;

}

template <class _InputIter, class _RandomAccessIter, class _Distance>

_RandomAccessIter __random_sample(_InputIter __first, _InputIter __last,

                                  _RandomAccessIter __stl_out,

                                  const _Distance __n)

{

  _Distance __m = 0;

  _Distance __t = __n;

  for ( ; __first != __last && __m < __n; ++__m, ++__first) 

    __stl_out[__m] = *__first;

  while (__first != __last) {

    ++__t;

    _Distance __M = __random_number(__t);

    if (__M < __n)

      __stl_out[__M] = *__first;

    ++__first;

  }

  return __stl_out + __m;

}