libstdc++
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00001 // Heap implementation -*- C++ -*- 00002 00003 // Copyright (C) 2001-2013 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 /* 00026 * 00027 * Copyright (c) 1994 00028 * Hewlett-Packard Company 00029 * 00030 * Permission to use, copy, modify, distribute and sell this software 00031 * and its documentation for any purpose is hereby granted without fee, 00032 * provided that the above copyright notice appear in all copies and 00033 * that both that copyright notice and this permission notice appear 00034 * in supporting documentation. Hewlett-Packard Company makes no 00035 * representations about the suitability of this software for any 00036 * purpose. It is provided "as is" without express or implied warranty. 00037 * 00038 * Copyright (c) 1997 00039 * Silicon Graphics Computer Systems, Inc. 00040 * 00041 * Permission to use, copy, modify, distribute and sell this software 00042 * and its documentation for any purpose is hereby granted without fee, 00043 * provided that the above copyright notice appear in all copies and 00044 * that both that copyright notice and this permission notice appear 00045 * in supporting documentation. Silicon Graphics makes no 00046 * representations about the suitability of this software for any 00047 * purpose. It is provided "as is" without express or implied warranty. 00048 */ 00049 00050 /** @file bits/stl_heap.h 00051 * This is an internal header file, included by other library headers. 00052 * Do not attempt to use it directly. @headername{queue} 00053 */ 00054 00055 #ifndef _STL_HEAP_H 00056 #define _STL_HEAP_H 1 00057 00058 #include <debug/debug.h> 00059 #include <bits/move.h> 00060 00061 namespace std _GLIBCXX_VISIBILITY(default) 00062 { 00063 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00064 00065 /** 00066 * @defgroup heap_algorithms Heap 00067 * @ingroup sorting_algorithms 00068 */ 00069 00070 template<typename _RandomAccessIterator, typename _Distance> 00071 _Distance 00072 __is_heap_until(_RandomAccessIterator __first, _Distance __n) 00073 { 00074 _Distance __parent = 0; 00075 for (_Distance __child = 1; __child < __n; ++__child) 00076 { 00077 if (__first[__parent] < __first[__child]) 00078 return __child; 00079 if ((__child & 1) == 0) 00080 ++__parent; 00081 } 00082 return __n; 00083 } 00084 00085 template<typename _RandomAccessIterator, typename _Distance, 00086 typename _Compare> 00087 _Distance 00088 __is_heap_until(_RandomAccessIterator __first, _Distance __n, 00089 _Compare __comp) 00090 { 00091 _Distance __parent = 0; 00092 for (_Distance __child = 1; __child < __n; ++__child) 00093 { 00094 if (__comp(__first[__parent], __first[__child])) 00095 return __child; 00096 if ((__child & 1) == 0) 00097 ++__parent; 00098 } 00099 return __n; 00100 } 00101 00102 // __is_heap, a predicate testing whether or not a range is a heap. 00103 // This function is an extension, not part of the C++ standard. 00104 template<typename _RandomAccessIterator, typename _Distance> 00105 inline bool 00106 __is_heap(_RandomAccessIterator __first, _Distance __n) 00107 { return std::__is_heap_until(__first, __n) == __n; } 00108 00109 template<typename _RandomAccessIterator, typename _Compare, 00110 typename _Distance> 00111 inline bool 00112 __is_heap(_RandomAccessIterator __first, _Compare __comp, _Distance __n) 00113 { return std::__is_heap_until(__first, __n, __comp) == __n; } 00114 00115 template<typename _RandomAccessIterator> 00116 inline bool 00117 __is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) 00118 { return std::__is_heap(__first, std::distance(__first, __last)); } 00119 00120 template<typename _RandomAccessIterator, typename _Compare> 00121 inline bool 00122 __is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, 00123 _Compare __comp) 00124 { return std::__is_heap(__first, __comp, std::distance(__first, __last)); } 00125 00126 // Heap-manipulation functions: push_heap, pop_heap, make_heap, sort_heap, 00127 // + is_heap and is_heap_until in C++0x. 00128 00129 template<typename _RandomAccessIterator, typename _Distance, typename _Tp> 00130 void 00131 __push_heap(_RandomAccessIterator __first, 00132 _Distance __holeIndex, _Distance __topIndex, _Tp __value) 00133 { 00134 _Distance __parent = (__holeIndex - 1) / 2; 00135 while (__holeIndex > __topIndex && *(__first + __parent) < __value) 00136 { 00137 *(__first + __holeIndex) = _GLIBCXX_MOVE(*(__first + __parent)); 00138 __holeIndex = __parent; 00139 __parent = (__holeIndex - 1) / 2; 00140 } 00141 *(__first + __holeIndex) = _GLIBCXX_MOVE(__value); 00142 } 00143 00144 /** 00145 * @brief Push an element onto a heap. 00146 * @param __first Start of heap. 00147 * @param __last End of heap + element. 00148 * @ingroup heap_algorithms 00149 * 00150 * This operation pushes the element at last-1 onto the valid heap 00151 * over the range [__first,__last-1). After completion, 00152 * [__first,__last) is a valid heap. 00153 */ 00154 template<typename _RandomAccessIterator> 00155 inline void 00156 push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) 00157 { 00158 typedef typename iterator_traits<_RandomAccessIterator>::value_type 00159 _ValueType; 00160 typedef typename iterator_traits<_RandomAccessIterator>::difference_type 00161 _DistanceType; 00162 00163 // concept requirements 00164 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< 00165 _RandomAccessIterator>) 00166 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>) 00167 __glibcxx_requires_valid_range(__first, __last); 00168 __glibcxx_requires_heap(__first, __last - 1); 00169 00170 _ValueType __value = _GLIBCXX_MOVE(*(__last - 1)); 00171 std::__push_heap(__first, _DistanceType((__last - __first) - 1), 00172 _DistanceType(0), _GLIBCXX_MOVE(__value)); 00173 } 00174 00175 template<typename _RandomAccessIterator, typename _Distance, typename _Tp, 00176 typename _Compare> 00177 void 00178 __push_heap(_RandomAccessIterator __first, _Distance __holeIndex, 00179 _Distance __topIndex, _Tp __value, _Compare __comp) 00180 { 00181 _Distance __parent = (__holeIndex - 1) / 2; 00182 while (__holeIndex > __topIndex 00183 && __comp(*(__first + __parent), __value)) 00184 { 00185 *(__first + __holeIndex) = _GLIBCXX_MOVE(*(__first + __parent)); 00186 __holeIndex = __parent; 00187 __parent = (__holeIndex - 1) / 2; 00188 } 00189 *(__first + __holeIndex) = _GLIBCXX_MOVE(__value); 00190 } 00191 00192 /** 00193 * @brief Push an element onto a heap using comparison functor. 00194 * @param __first Start of heap. 00195 * @param __last End of heap + element. 00196 * @param __comp Comparison functor. 00197 * @ingroup heap_algorithms 00198 * 00199 * This operation pushes the element at __last-1 onto the valid 00200 * heap over the range [__first,__last-1). After completion, 00201 * [__first,__last) is a valid heap. Compare operations are 00202 * performed using comp. 00203 */ 00204 template<typename _RandomAccessIterator, typename _Compare> 00205 inline void 00206 push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, 00207 _Compare __comp) 00208 { 00209 typedef typename iterator_traits<_RandomAccessIterator>::value_type 00210 _ValueType; 00211 typedef typename iterator_traits<_RandomAccessIterator>::difference_type 00212 _DistanceType; 00213 00214 // concept requirements 00215 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< 00216 _RandomAccessIterator>) 00217 __glibcxx_requires_valid_range(__first, __last); 00218 __glibcxx_requires_heap_pred(__first, __last - 1, __comp); 00219 00220 _ValueType __value = _GLIBCXX_MOVE(*(__last - 1)); 00221 std::__push_heap(__first, _DistanceType((__last - __first) - 1), 00222 _DistanceType(0), _GLIBCXX_MOVE(__value), __comp); 00223 } 00224 00225 template<typename _RandomAccessIterator, typename _Distance, typename _Tp> 00226 void 00227 __adjust_heap(_RandomAccessIterator __first, _Distance __holeIndex, 00228 _Distance __len, _Tp __value) 00229 { 00230 const _Distance __topIndex = __holeIndex; 00231 _Distance __secondChild = __holeIndex; 00232 while (__secondChild < (__len - 1) / 2) 00233 { 00234 __secondChild = 2 * (__secondChild + 1); 00235 if (*(__first + __secondChild) < *(__first + (__secondChild - 1))) 00236 __secondChild--; 00237 *(__first + __holeIndex) = _GLIBCXX_MOVE(*(__first + __secondChild)); 00238 __holeIndex = __secondChild; 00239 } 00240 if ((__len & 1) == 0 && __secondChild == (__len - 2) / 2) 00241 { 00242 __secondChild = 2 * (__secondChild + 1); 00243 *(__first + __holeIndex) = _GLIBCXX_MOVE(*(__first 00244 + (__secondChild - 1))); 00245 __holeIndex = __secondChild - 1; 00246 } 00247 std::__push_heap(__first, __holeIndex, __topIndex, 00248 _GLIBCXX_MOVE(__value)); 00249 } 00250 00251 template<typename _RandomAccessIterator> 00252 inline void 00253 __pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, 00254 _RandomAccessIterator __result) 00255 { 00256 typedef typename iterator_traits<_RandomAccessIterator>::value_type 00257 _ValueType; 00258 typedef typename iterator_traits<_RandomAccessIterator>::difference_type 00259 _DistanceType; 00260 00261 _ValueType __value = _GLIBCXX_MOVE(*__result); 00262 *__result = _GLIBCXX_MOVE(*__first); 00263 std::__adjust_heap(__first, _DistanceType(0), 00264 _DistanceType(__last - __first), 00265 _GLIBCXX_MOVE(__value)); 00266 } 00267 00268 /** 00269 * @brief Pop an element off a heap. 00270 * @param __first Start of heap. 00271 * @param __last End of heap. 00272 * @pre [__first, __last) is a valid, non-empty range. 00273 * @ingroup heap_algorithms 00274 * 00275 * This operation pops the top of the heap. The elements __first 00276 * and __last-1 are swapped and [__first,__last-1) is made into a 00277 * heap. 00278 */ 00279 template<typename _RandomAccessIterator> 00280 inline void 00281 pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) 00282 { 00283 typedef typename iterator_traits<_RandomAccessIterator>::value_type 00284 _ValueType; 00285 00286 // concept requirements 00287 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< 00288 _RandomAccessIterator>) 00289 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>) 00290 __glibcxx_requires_non_empty_range(__first, __last); 00291 __glibcxx_requires_valid_range(__first, __last); 00292 __glibcxx_requires_heap(__first, __last); 00293 00294 if (__last - __first > 1) 00295 { 00296 --__last; 00297 std::__pop_heap(__first, __last, __last); 00298 } 00299 } 00300 00301 template<typename _RandomAccessIterator, typename _Distance, 00302 typename _Tp, typename _Compare> 00303 void 00304 __adjust_heap(_RandomAccessIterator __first, _Distance __holeIndex, 00305 _Distance __len, _Tp __value, _Compare __comp) 00306 { 00307 const _Distance __topIndex = __holeIndex; 00308 _Distance __secondChild = __holeIndex; 00309 while (__secondChild < (__len - 1) / 2) 00310 { 00311 __secondChild = 2 * (__secondChild + 1); 00312 if (__comp(*(__first + __secondChild), 00313 *(__first + (__secondChild - 1)))) 00314 __secondChild--; 00315 *(__first + __holeIndex) = _GLIBCXX_MOVE(*(__first + __secondChild)); 00316 __holeIndex = __secondChild; 00317 } 00318 if ((__len & 1) == 0 && __secondChild == (__len - 2) / 2) 00319 { 00320 __secondChild = 2 * (__secondChild + 1); 00321 *(__first + __holeIndex) = _GLIBCXX_MOVE(*(__first 00322 + (__secondChild - 1))); 00323 __holeIndex = __secondChild - 1; 00324 } 00325 std::__push_heap(__first, __holeIndex, __topIndex, 00326 _GLIBCXX_MOVE(__value), __comp); 00327 } 00328 00329 template<typename _RandomAccessIterator, typename _Compare> 00330 inline void 00331 __pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, 00332 _RandomAccessIterator __result, _Compare __comp) 00333 { 00334 typedef typename iterator_traits<_RandomAccessIterator>::value_type 00335 _ValueType; 00336 typedef typename iterator_traits<_RandomAccessIterator>::difference_type 00337 _DistanceType; 00338 00339 _ValueType __value = _GLIBCXX_MOVE(*__result); 00340 *__result = _GLIBCXX_MOVE(*__first); 00341 std::__adjust_heap(__first, _DistanceType(0), 00342 _DistanceType(__last - __first), 00343 _GLIBCXX_MOVE(__value), __comp); 00344 } 00345 00346 /** 00347 * @brief Pop an element off a heap using comparison functor. 00348 * @param __first Start of heap. 00349 * @param __last End of heap. 00350 * @param __comp Comparison functor to use. 00351 * @ingroup heap_algorithms 00352 * 00353 * This operation pops the top of the heap. The elements __first 00354 * and __last-1 are swapped and [__first,__last-1) is made into a 00355 * heap. Comparisons are made using comp. 00356 */ 00357 template<typename _RandomAccessIterator, typename _Compare> 00358 inline void 00359 pop_heap(_RandomAccessIterator __first, 00360 _RandomAccessIterator __last, _Compare __comp) 00361 { 00362 // concept requirements 00363 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< 00364 _RandomAccessIterator>) 00365 __glibcxx_requires_valid_range(__first, __last); 00366 __glibcxx_requires_non_empty_range(__first, __last); 00367 __glibcxx_requires_heap_pred(__first, __last, __comp); 00368 00369 if (__last - __first > 1) 00370 { 00371 --__last; 00372 std::__pop_heap(__first, __last, __last, __comp); 00373 } 00374 } 00375 00376 /** 00377 * @brief Construct a heap over a range. 00378 * @param __first Start of heap. 00379 * @param __last End of heap. 00380 * @ingroup heap_algorithms 00381 * 00382 * This operation makes the elements in [__first,__last) into a heap. 00383 */ 00384 template<typename _RandomAccessIterator> 00385 void 00386 make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) 00387 { 00388 typedef typename iterator_traits<_RandomAccessIterator>::value_type 00389 _ValueType; 00390 typedef typename iterator_traits<_RandomAccessIterator>::difference_type 00391 _DistanceType; 00392 00393 // concept requirements 00394 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< 00395 _RandomAccessIterator>) 00396 __glibcxx_function_requires(_LessThanComparableConcept<_ValueType>) 00397 __glibcxx_requires_valid_range(__first, __last); 00398 00399 if (__last - __first < 2) 00400 return; 00401 00402 const _DistanceType __len = __last - __first; 00403 _DistanceType __parent = (__len - 2) / 2; 00404 while (true) 00405 { 00406 _ValueType __value = _GLIBCXX_MOVE(*(__first + __parent)); 00407 std::__adjust_heap(__first, __parent, __len, _GLIBCXX_MOVE(__value)); 00408 if (__parent == 0) 00409 return; 00410 __parent--; 00411 } 00412 } 00413 00414 /** 00415 * @brief Construct a heap over a range using comparison functor. 00416 * @param __first Start of heap. 00417 * @param __last End of heap. 00418 * @param __comp Comparison functor to use. 00419 * @ingroup heap_algorithms 00420 * 00421 * This operation makes the elements in [__first,__last) into a heap. 00422 * Comparisons are made using __comp. 00423 */ 00424 template<typename _RandomAccessIterator, typename _Compare> 00425 void 00426 make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, 00427 _Compare __comp) 00428 { 00429 typedef typename iterator_traits<_RandomAccessIterator>::value_type 00430 _ValueType; 00431 typedef typename iterator_traits<_RandomAccessIterator>::difference_type 00432 _DistanceType; 00433 00434 // concept requirements 00435 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< 00436 _RandomAccessIterator>) 00437 __glibcxx_requires_valid_range(__first, __last); 00438 00439 if (__last - __first < 2) 00440 return; 00441 00442 const _DistanceType __len = __last - __first; 00443 _DistanceType __parent = (__len - 2) / 2; 00444 while (true) 00445 { 00446 _ValueType __value = _GLIBCXX_MOVE(*(__first + __parent)); 00447 std::__adjust_heap(__first, __parent, __len, _GLIBCXX_MOVE(__value), 00448 __comp); 00449 if (__parent == 0) 00450 return; 00451 __parent--; 00452 } 00453 } 00454 00455 /** 00456 * @brief Sort a heap. 00457 * @param __first Start of heap. 00458 * @param __last End of heap. 00459 * @ingroup heap_algorithms 00460 * 00461 * This operation sorts the valid heap in the range [__first,__last). 00462 */ 00463 template<typename _RandomAccessIterator> 00464 void 00465 sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) 00466 { 00467 // concept requirements 00468 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< 00469 _RandomAccessIterator>) 00470 __glibcxx_function_requires(_LessThanComparableConcept< 00471 typename iterator_traits<_RandomAccessIterator>::value_type>) 00472 __glibcxx_requires_valid_range(__first, __last); 00473 __glibcxx_requires_heap(__first, __last); 00474 00475 while (__last - __first > 1) 00476 { 00477 --__last; 00478 std::__pop_heap(__first, __last, __last); 00479 } 00480 } 00481 00482 /** 00483 * @brief Sort a heap using comparison functor. 00484 * @param __first Start of heap. 00485 * @param __last End of heap. 00486 * @param __comp Comparison functor to use. 00487 * @ingroup heap_algorithms 00488 * 00489 * This operation sorts the valid heap in the range [__first,__last). 00490 * Comparisons are made using __comp. 00491 */ 00492 template<typename _RandomAccessIterator, typename _Compare> 00493 void 00494 sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, 00495 _Compare __comp) 00496 { 00497 // concept requirements 00498 __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept< 00499 _RandomAccessIterator>) 00500 __glibcxx_requires_valid_range(__first, __last); 00501 __glibcxx_requires_heap_pred(__first, __last, __comp); 00502 00503 while (__last - __first > 1) 00504 { 00505 --__last; 00506 std::__pop_heap(__first, __last, __last, __comp); 00507 } 00508 } 00509 00510 #if __cplusplus >= 201103L 00511 /** 00512 * @brief Search the end of a heap. 00513 * @param __first Start of range. 00514 * @param __last End of range. 00515 * @return An iterator pointing to the first element not in the heap. 00516 * @ingroup heap_algorithms 00517 * 00518 * This operation returns the last iterator i in [__first, __last) for which 00519 * the range [__first, i) is a heap. 00520 */ 00521 template<typename _RandomAccessIterator> 00522 inline _RandomAccessIterator 00523 is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last) 00524 { 00525 // concept requirements 00526 __glibcxx_function_requires(_RandomAccessIteratorConcept< 00527 _RandomAccessIterator>) 00528 __glibcxx_function_requires(_LessThanComparableConcept< 00529 typename iterator_traits<_RandomAccessIterator>::value_type>) 00530 __glibcxx_requires_valid_range(__first, __last); 00531 00532 return __first + std::__is_heap_until(__first, std::distance(__first, 00533 __last)); 00534 } 00535 00536 /** 00537 * @brief Search the end of a heap using comparison functor. 00538 * @param __first Start of range. 00539 * @param __last End of range. 00540 * @param __comp Comparison functor to use. 00541 * @return An iterator pointing to the first element not in the heap. 00542 * @ingroup heap_algorithms 00543 * 00544 * This operation returns the last iterator i in [__first, __last) for which 00545 * the range [__first, i) is a heap. Comparisons are made using __comp. 00546 */ 00547 template<typename _RandomAccessIterator, typename _Compare> 00548 inline _RandomAccessIterator 00549 is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, 00550 _Compare __comp) 00551 { 00552 // concept requirements 00553 __glibcxx_function_requires(_RandomAccessIteratorConcept< 00554 _RandomAccessIterator>) 00555 __glibcxx_requires_valid_range(__first, __last); 00556 00557 return __first + std::__is_heap_until(__first, std::distance(__first, 00558 __last), 00559 __comp); 00560 } 00561 00562 /** 00563 * @brief Determines whether a range is a heap. 00564 * @param __first Start of range. 00565 * @param __last End of range. 00566 * @return True if range is a heap, false otherwise. 00567 * @ingroup heap_algorithms 00568 */ 00569 template<typename _RandomAccessIterator> 00570 inline bool 00571 is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last) 00572 { return std::is_heap_until(__first, __last) == __last; } 00573 00574 /** 00575 * @brief Determines whether a range is a heap using comparison functor. 00576 * @param __first Start of range. 00577 * @param __last End of range. 00578 * @param __comp Comparison functor to use. 00579 * @return True if range is a heap, false otherwise. 00580 * @ingroup heap_algorithms 00581 */ 00582 template<typename _RandomAccessIterator, typename _Compare> 00583 inline bool 00584 is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, 00585 _Compare __comp) 00586 { return std::is_heap_until(__first, __last, __comp) == __last; } 00587 #endif 00588 00589 _GLIBCXX_END_NAMESPACE_VERSION 00590 } // namespace 00591 00592 #endif /* _STL_HEAP_H */