[thirdparty/gcc.git] / libstdc++-v3 / include / ext / algorithm

// Algorithm extensions -*- C++ -*-

// Copyright (C) 2001 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// As a special exception, you may use this file as part of a free software
// library without restriction.  Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License.  This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.

/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1996
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 */

#ifndef _EXT_ALGORITHM
#define _EXT_ALGORITHM

#include <bits/std_algorithm.h>

namespace __gnu_cxx
{
  // count and count_if: this version, whose return type is void, was present
  // in the HP STL, and is retained as an extension for backward compatibility.

  template<typename _InputIter, typename _Tp, typename _Size>
    void
    count(_InputIter __first, _InputIter __last,
	  const _Tp& __value,
	  _Size& __n)
    {
      // concept requirements
      __glibcpp_function_requires(_InputIteratorConcept<_InputIter>)
      __glibcpp_function_requires(_EqualityComparableConcept<
	    typename std::iterator_traits<_InputIter>::value_type >)
      __glibcpp_function_requires(_EqualityComparableConcept<_Tp>)
      for ( ; __first != __last; ++__first)
	if (*__first == __value)
	  ++__n;
    }

  template<typename _InputIter, typename _Predicate, typename _Size>
    void
    count_if(_InputIter __first, _InputIter __last,
	     _Predicate __pred,
	     _Size& __n)
    {
      // concept requirements
      __glibcpp_function_requires(_InputIteratorConcept<_InputIter>)
      __glibcpp_function_requires(_UnaryPredicateConcept<_Predicate,
	    typename std::iterator_traits<_InputIter>::value_type>)
      for ( ; __first != __last; ++__first)
	if (__pred(*__first))
	  ++__n;
    }

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

  template<typename _ForwardIter, typename _OutputIter, typename _Distance>
    _OutputIter
    random_sample_n(_ForwardIter __first, _ForwardIter __last,
                    _OutputIter __out, const _Distance __n)
    {
      // concept requirements
      __glibcpp_function_requires(_ForwardIteratorConcept<_ForwardIter>)
      __glibcpp_function_requires(_OutputIteratorConcept<_OutputIter,
		typename std::iterator_traits<_ForwardIter>::value_type>)

      _Distance __remaining = std::distance(__first, __last);
      _Distance __m = std::min(__n, __remaining);

      while (__m > 0) {
	if (std::__random_number(__remaining) < __m) {
	      *__out = *__first;
	      ++__out;
	      --__m;
	}

	--__remaining;
	++__first;
      }
      return __out;
    }

  template<typename _ForwardIter, typename _OutputIter, typename _Distance,
	   typename _RandomNumberGenerator>
    _OutputIter
    random_sample_n(_ForwardIter __first, _ForwardIter __last,
                   _OutputIter __out, const _Distance __n, 
		   _RandomNumberGenerator& __rand)
    {
      // concept requirements
      __glibcpp_function_requires(_ForwardIteratorConcept<_ForwardIter>)
      __glibcpp_function_requires(_OutputIteratorConcept<_OutputIter,
		typename std::iterator_traits<_ForwardIter>::value_type>)
      __glibcpp_function_requires(_UnaryFunctionConcept<
		_RandomNumberGenerator, _Distance, _Distance>)

      _Distance __remaining = std::distance(__first, __last);
      _Distance __m = std::min(__n, __remaining);

      while (__m > 0) {
	if (__rand(__remaining) < __m) {
	      *__out = *__first;
	      ++__out;
	      --__m;
	}

	--__remaining;
	++__first;
      }
      return __out;
    }

  template<typename _InputIter, typename _RandomAccessIter, typename _Distance>
    _RandomAccessIter
    __random_sample(_InputIter __first, _InputIter __last,
		    _RandomAccessIter __out,
		    const _Distance __n)
    {
      _Distance __m = 0;
      _Distance __t = __n;
      for ( ; __first != __last && __m < __n; ++__m, ++__first) 
	__out[__m] = *__first;

      while (__first != __last) {
	++__t;
	_Distance __M = std::__random_number(__t);
	if (__M < __n)
	  __out[__M] = *__first;
	++__first;
      }

      return __out + __m;
    }

  template<typename _InputIter, typename _RandomAccessIter,
	   typename _RandomNumberGenerator, typename _Distance>
    _RandomAccessIter
    __random_sample(_InputIter __first, _InputIter __last,
		    _RandomAccessIter __out,
		    _RandomNumberGenerator& __rand,
		    const _Distance __n)
    {
      // concept requirements
      __glibcpp_function_requires(_UnaryFunctionConcept<
	    _RandomNumberGenerator, _Distance, _Distance>)

      _Distance __m = 0;
      _Distance __t = __n;
      for ( ; __first != __last && __m < __n; ++__m, ++__first)
	__out[__m] = *__first;

      while (__first != __last) {
	++__t;
	_Distance __M = __rand(__t);
	if (__M < __n)
	  __out[__M] = *__first;
	++__first;
      }

      return __out + __m;
    }

  template<typename _InputIter, typename _RandomAccessIter>
    inline _RandomAccessIter
    random_sample(_InputIter __first, _InputIter __last,
		  _RandomAccessIter __out_first, _RandomAccessIter __out_last) 
    {
      // concept requirements
      __glibcpp_function_requires(_InputIteratorConcept<_InputIter>)
      __glibcpp_function_requires(_Mutable_RandomAccessIteratorConcept<
	    _RandomAccessIter>)

      return __random_sample(__first, __last,
			     __out_first, __out_last - __out_first);
    }

  template<typename _InputIter, typename _RandomAccessIter, 
	   typename _RandomNumberGenerator>
    inline _RandomAccessIter
    random_sample(_InputIter __first, _InputIter __last,
		  _RandomAccessIter __out_first, _RandomAccessIter __out_last,
		  _RandomNumberGenerator& __rand) 
    {
      // concept requirements
      __glibcpp_function_requires(_InputIteratorConcept<_InputIter>)
      __glibcpp_function_requires(_Mutable_RandomAccessIteratorConcept<
	    _RandomAccessIter>)

      return __random_sample(__first, __last,
			     __out_first, __rand,
			     __out_last - __out_first);
    }
  
  // is_heap, a predicate testing whether or not a range is
  // a heap.  This function is an extension, not part of the C++
  // standard.

  template<typename _RandomAccessIter, typename _Distance>
    bool
    __is_heap(_RandomAccessIter __first, _Distance __n)
    {
      _Distance __parent = 0;
      for (_Distance __child = 1; __child < __n; ++__child) {
	if (__first[__parent] < __first[__child]) 
	  return false;
	if ((__child & 1) == 0)
	  ++__parent;
      }
      return true;
    }

  template<typename _RandomAccessIter, typename _Distance,
           typename _StrictWeakOrdering>
    bool
    __is_heap(_RandomAccessIter __first, _StrictWeakOrdering __comp,
	      _Distance __n)
    {
      _Distance __parent = 0;
      for (_Distance __child = 1; __child < __n; ++__child) {
	if (__comp(__first[__parent], __first[__child]))
	  return false;
	if ((__child & 1) == 0)
	  ++__parent;
      }
      return true;
    }

  template<typename _RandomAccessIter>
    inline bool
    is_heap(_RandomAccessIter __first, _RandomAccessIter __last)
    {
      // concept requirements
      __glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIter>)
      __glibcpp_function_requires(_LessThanComparableConcept<
	    typename std::iterator_traits<_RandomAccessIter>::value_type>)

      return __is_heap(__first, __last - __first);
    }

  template<typename _RandomAccessIter, typename _StrictWeakOrdering>
    inline bool
    is_heap(_RandomAccessIter __first, _RandomAccessIter __last,
	    _StrictWeakOrdering __comp)
    {
      // concept requirements
      __glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIter>)
      __glibcpp_function_requires(_BinaryPredicateConcept<_StrictWeakOrdering,
	    typename std::iterator_traits<_RandomAccessIter>::value_type, 
	    typename std::iterator_traits<_RandomAccessIter>::value_type>)

      return __is_heap(__first, __comp, __last - __first);
    }

  // is_sorted, a predicated testing whether a range is sorted in
  // nondescending order.  This is an extension, not part of the C++
  // standard.

  template<typename _ForwardIter>
    bool
    is_sorted(_ForwardIter __first, _ForwardIter __last)
    {
      // concept requirements
      __glibcpp_function_requires(_ForwardIteratorConcept<_ForwardIter>)
      __glibcpp_function_requires(_LessThanComparableConcept<
	    typename std::iterator_traits<_ForwardIter>::value_type>)

      if (__first == __last)
	return true;

      _ForwardIter __next = __first;
      for (++__next; __next != __last; __first = __next, ++__next) {
	if (*__next < *__first)
	  return false;
      }

      return true;
    }

  template<typename _ForwardIter, typename _StrictWeakOrdering>
    bool
    is_sorted(_ForwardIter __first, _ForwardIter __last, _StrictWeakOrdering __comp)
    {
      // concept requirements
      __glibcpp_function_requires(_ForwardIteratorConcept<_ForwardIter>)
      __glibcpp_function_requires(_BinaryPredicateConcept<_StrictWeakOrdering,
	    typename std::iterator_traits<_ForwardIter>::value_type, 
	    typename std::iterator_traits<_ForwardIter>::value_type>)

      if (__first == __last)
	return true;

      _ForwardIter __next = __first;
      for (++__next; __next != __last; __first = __next, ++__next) {
	if (__comp(*__next, *__first))
	  return false;
      }

      return true;
    }

} // namespace __gnu_cxx

#endif /* _EXT_ALGORITHM */
Commit	Line	Data
2c1bc4eb PC	1	// Algorithm extensions -- C++ --
	2
	3	// Copyright (C) 2001 Free Software Foundation, Inc.
	4	//
	5	// This file is part of the GNU ISO C++ Library. This library is free
	6	// software; you can redistribute it and/or modify it under the
	7	// terms of the GNU General Public License as published by the
	8	// Free Software Foundation; either version 2, or (at your option)
	9	// any later version.
	10
	11	// This library is distributed in the hope that it will be useful,
	12	// but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	// GNU General Public License for more details.
	15
	16	// You should have received a copy of the GNU General Public License along
	17	// with this library; see the file COPYING. If not, write to the Free
	18	// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
	19	// USA.
	20
	21	// As a special exception, you may use this file as part of a free software
	22	// library without restriction. Specifically, if other files instantiate
	23	// templates or use macros or inline functions from this file, or you compile
	24	// this file and link it with other files to produce an executable, this
	25	// file does not by itself cause the resulting executable to be covered by
	26	// the GNU General Public License. This exception does not however
	27	// invalidate any other reasons why the executable file might be covered by
	28	// the GNU General Public License.
	29
	30	/*
	31	*
	32	* Copyright (c) 1994
	33	* Hewlett-Packard Company
	34	*
	35	* Permission to use, copy, modify, distribute and sell this software
	36	* and its documentation for any purpose is hereby granted without fee,
	37	* provided that the above copyright notice appear in all copies and
	38	* that both that copyright notice and this permission notice appear
	39	* in supporting documentation. Hewlett-Packard Company makes no
	40	* representations about the suitability of this software for any
	41	* purpose. It is provided "as is" without express or implied warranty.
	42	*
	43	*
	44	* Copyright (c) 1996
	45	* Silicon Graphics Computer Systems, Inc.
	46	*
	47	* Permission to use, copy, modify, distribute and sell this software
	48	* and its documentation for any purpose is hereby granted without fee,
	49	* provided that the above copyright notice appear in all copies and
	50	* that both that copyright notice and this permission notice appear
	51	* in supporting documentation. Silicon Graphics makes no
	52	* representations about the suitability of this software for any
	53	* purpose. It is provided "as is" without express or implied warranty.
	54	*/
	55
	56	#ifndef _EXT_ALGORITHM
	57	#define _EXT_ALGORITHM
	58
	59	#include <bits/std_algorithm.h>
	60
	61	namespace __gnu_cxx
	62	{
	63	// count and count_if: this version, whose return type is void, was present
	64	// in the HP STL, and is retained as an extension for backward compatibility.
65
66	template<typename _InputIter, typename _Tp, typename _Size>
67	void
68	count(_InputIter __first, _InputIter __last,
69	const _Tp& __value,
70	_Size& __n)
71	{
72	// concept requirements
73	__glibcpp_function_requires(_InputIteratorConcept<_InputIter>)
74	__glibcpp_function_requires(_EqualityComparableConcept<
75	typename std::iterator_traits<_InputIter>::value_type >)
76	__glibcpp_function_requires(_EqualityComparableConcept<_Tp>)
77	for ( ; __first != __last; ++__first)
78	if (*__first == __value)
79	++__n;
80	}
81
82	template<typename _InputIter, typename _Predicate, typename _Size>
83	void
84	count_if(_InputIter __first, _InputIter __last,
85	_Predicate __pred,
86	_Size& __n)
87	{
88	// concept requirements
89	__glibcpp_function_requires(_InputIteratorConcept<_InputIter>)
90	__glibcpp_function_requires(_UnaryPredicateConcept<_Predicate,
91	typename std::iterator_traits<_InputIter>::value_type>)
92	for ( ; __first != __last; ++__first)
93	if (__pred(*__first))
94	++__n;
95	}
96
97	// random_sample and random_sample_n (extensions, not part of the standard).
98
99	template<typename _ForwardIter, typename _OutputIter, typename _Distance>
100	_OutputIter
101	random_sample_n(_ForwardIter __first, _ForwardIter __last,
102	_OutputIter __out, const _Distance __n)
103	{
104	// concept requirements
105	__glibcpp_function_requires(_ForwardIteratorConcept<_ForwardIter>)
106	__glibcpp_function_requires(_OutputIteratorConcept<_OutputIter,
107	typename std::iterator_traits<_ForwardIter>::value_type>)
108
109	_Distance __remaining = std::distance(__first, __last);
110	_Distance __m = std::min(__n, __remaining);
111
112	while (__m > 0) {
113	if (std::__random_number(__remaining) < __m) {
114	__out = __first;
115	++__out;
116	--__m;
117	}
118
119	--__remaining;
120	++__first;
121	}
122	return __out;
123	}
124
125	template<typename _ForwardIter, typename _OutputIter, typename _Distance,
126	typename _RandomNumberGenerator>
127	_OutputIter
128	random_sample_n(_ForwardIter __first, _ForwardIter __last,
129	_OutputIter __out, const _Distance __n,
130	_RandomNumberGenerator& __rand)
131	{
132	// concept requirements
133	__glibcpp_function_requires(_ForwardIteratorConcept<_ForwardIter>)
134	__glibcpp_function_requires(_OutputIteratorConcept<_OutputIter,
135	typename std::iterator_traits<_ForwardIter>::value_type>)
136	__glibcpp_function_requires(_UnaryFunctionConcept<
137	_RandomNumberGenerator, _Distance, _Distance>)
138
139	_Distance __remaining = std::distance(__first, __last);
140	_Distance __m = std::min(__n, __remaining);
141
142	while (__m > 0) {
143	if (__rand(__remaining) < __m) {
144	__out = __first;
145	++__out;
146	--__m;
147	}
148
149	--__remaining;
150	++__first;
151	}
152	return __out;
153	}
154
155	template<typename _InputIter, typename _RandomAccessIter, typename _Distance>
156	_RandomAccessIter
157	__random_sample(_InputIter __first, _InputIter __last,
158	_RandomAccessIter __out,
159	const _Distance __n)
160	{
161	_Distance __m = 0;
162	_Distance __t = __n;
163	for ( ; __first != __last && __m < __n; ++__m, ++__first)
164	__out[__m] = *__first;
165
166	while (__first != __last) {
167	++__t;
168	_Distance __M = std::__random_number(__t);
169	if (__M < __n)
170	__out[__M] = *__first;
171	++__first;
172	}
173
174	return __out + __m;
175	}
176
177	template<typename _InputIter, typename _RandomAccessIter,
178	typename _RandomNumberGenerator, typename _Distance>
179	_RandomAccessIter
180	__random_sample(_InputIter __first, _InputIter __last,
181	_RandomAccessIter __out,
182	_RandomNumberGenerator& __rand,
183	const _Distance __n)
184	{
185	// concept requirements
186	__glibcpp_function_requires(_UnaryFunctionConcept<
187	_RandomNumberGenerator, _Distance, _Distance>)
188
189	_Distance __m = 0;
190	_Distance __t = __n;
191	for ( ; __first != __last && __m < __n; ++__m, ++__first)
192	__out[__m] = *__first;
193
194	while (__first != __last) {
195	++__t;
196	_Distance __M = __rand(__t);
197	if (__M < __n)
198	__out[__M] = *__first;
199	++__first;
200	}
201
202	return __out + __m;
203	}
204
205	template<typename _InputIter, typename _RandomAccessIter>
206	inline _RandomAccessIter
207	random_sample(_InputIter __first, _InputIter __last,
208	_RandomAccessIter __out_first, _RandomAccessIter __out_last)
209	{
210	// concept requirements
211	__glibcpp_function_requires(_InputIteratorConcept<_InputIter>)
212	__glibcpp_function_requires(_Mutable_RandomAccessIteratorConcept<
213	_RandomAccessIter>)
214
215	return __random_sample(__first, __last,
216	__out_first, __out_last - __out_first);
217	}
218
219	template<typename _InputIter, typename _RandomAccessIter,
220	typename _RandomNumberGenerator>
221	inline _RandomAccessIter
222	random_sample(_InputIter __first, _InputIter __last,
223	_RandomAccessIter __out_first, _RandomAccessIter __out_last,
224	_RandomNumberGenerator& __rand)
225	{
226	// concept requirements
227	__glibcpp_function_requires(_InputIteratorConcept<_InputIter>)
228	__glibcpp_function_requires(_Mutable_RandomAccessIteratorConcept<
229	_RandomAccessIter>)
230
231	return __random_sample(__first, __last,
232	__out_first, __rand,
233	__out_last - __out_first);
234	}
235
236	// is_heap, a predicate testing whether or not a range is
237	// a heap. This function is an extension, not part of the C++
238	// standard.
239
240	template<typename _RandomAccessIter, typename _Distance>
241	bool
242	__is_heap(_RandomAccessIter __first, _Distance __n)
243	{
244	_Distance __parent = 0;
245	for (_Distance __child = 1; __child < __n; ++__child) {
246	if (__first[__parent] < __first[__child])
247	return false;
248	if ((__child & 1) == 0)
249	++__parent;
250	}
251	return true;
252	}
253
254	template<typename _RandomAccessIter, typename _Distance,
255	typename _StrictWeakOrdering>
256	bool
257	__is_heap(_RandomAccessIter __first, _StrictWeakOrdering __comp,
258	_Distance __n)
259	{
260	_Distance __parent = 0;
261	for (_Distance __child = 1; __child < __n; ++__child) {
262	if (__comp(__first[__parent], __first[__child]))
263	return false;
264	if ((__child & 1) == 0)
265	++__parent;
266	}
267	return true;
268	}
269
270	template<typename _RandomAccessIter>
271	inline bool
272	is_heap(_RandomAccessIter __first, _RandomAccessIter __last)
273	{
274	// concept requirements
275	__glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIter>)
276	__glibcpp_function_requires(_LessThanComparableConcept<
277	typename std::iterator_traits<_RandomAccessIter>::value_type>)
278
279	return __is_heap(__first, __last - __first);
280	}
281
282	template<typename _RandomAccessIter, typename _StrictWeakOrdering>
283	inline bool
284	is_heap(_RandomAccessIter __first, _RandomAccessIter __last,
285	_StrictWeakOrdering __comp)
286	{
287	// concept requirements
288	__glibcpp_function_requires(_RandomAccessIteratorConcept<_RandomAccessIter>)
289	__glibcpp_function_requires(_BinaryPredicateConcept<_StrictWeakOrdering,
290	typename std::iterator_traits<_RandomAccessIter>::value_type,
291	typename std::iterator_traits<_RandomAccessIter>::value_type>)
292
293	return __is_heap(__first, __comp, __last - __first);
294	}
295
296	// is_sorted, a predicated testing whether a range is sorted in
297	// nondescending order. This is an extension, not part of the C++
298	// standard.
299
300	template<typename _ForwardIter>
301	bool
302	is_sorted(_ForwardIter __first, _ForwardIter __last)
303	{
304	// concept requirements
305	__glibcpp_function_requires(_ForwardIteratorConcept<_ForwardIter>)
306	__glibcpp_function_requires(_LessThanComparableConcept<
307	typename std::iterator_traits<_ForwardIter>::value_type>)
308
309	if (__first == __last)
310	return true;
311
312	_ForwardIter __next = __first;
313	for (++__next; __next != __last; __first = __next, ++__next) {
314	if (__next < __first)
315	return false;
316	}
317
318	return true;
319	}
320
321	template<typename _ForwardIter, typename _StrictWeakOrdering>
322	bool
323	is_sorted(_ForwardIter __first, _ForwardIter __last, _StrictWeakOrdering __comp)
324	{
325	// concept requirements
326	__glibcpp_function_requires(_ForwardIteratorConcept<_ForwardIter>)
327	__glibcpp_function_requires(_BinaryPredicateConcept<_StrictWeakOrdering,
328	typename std::iterator_traits<_ForwardIter>::value_type,
329	typename std::iterator_traits<_ForwardIter>::value_type>)
330
331	if (__first == __last)
332	return true;
333
334	_ForwardIter __next = __first;
335	for (++__next; __next != __last; __first = __next, ++__next) {
336	if (__comp(__next, __first))
337	return false;
338	}
339
340	return true;
341	}
342
343	} // namespace __gnu_cxx
344
345	#endif /* _EXT_ALGORITHM */