Small bug fixes.
3 * This file is a part of LEMON, a generic C++ optimization library
5 * Copyright (C) 2003-2007
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
9 * Permission to use, modify and distribute this software is granted
10 * provided that this copyright notice appears in all copies. For
11 * precise terms see the accompanying LICENSE file.
13 * This software is provided "AS IS" with no warranty of any kind,
14 * express or implied, and with no claim as to its suitability for any
32 #include <lemon/error.h>
36 namespace _radix_sort_bits {
38 template <typename Value>
40 const Value& operator()(const Value& val) {
47 template <typename Value, typename Iterator, typename Functor>
48 Iterator radixSortPartition(Iterator first, Iterator last,
49 Functor functor, Value mask) {
50 while (first != last && !(functor(*first) & mask)) {
57 while (first != last && (functor(*last) & mask)) {
63 std::iter_swap(first, last);
65 if (!(first < last)) {
69 while (!(functor(*first) & mask)) {
73 while (functor(*last) & mask) {
76 if (!(first < last)) {
79 std::iter_swap(first, last);
84 template <typename Iterator, typename Functor>
85 Iterator radixSortSignPartition(Iterator first, Iterator last,
87 while (first != last && functor(*first) < 0) {
94 while (first != last && functor(*last) >= 0) {
100 std::iter_swap(first, last);
102 if (!(first < last)) {
106 while (functor(*first) < 0) {
110 while (functor(*last) >= 0) {
113 if (!(first < last)) {
116 std::iter_swap(first, last);
121 template <typename Value, typename Iterator, typename Functor>
122 void radixIntroSort(Iterator first, Iterator last,
123 Functor functor, Value mask) {
124 while (mask != 0 && last - first > 1) {
125 Iterator cut = radixSortPartition(first, last, functor, mask);
127 radixIntroSort(first, cut, functor, mask);
132 template <typename Value, typename Iterator, typename Functor>
133 void radixSignedSort(Iterator first, Iterator last, Functor functor) {
134 Iterator cut = radixSortSignPartition(first, last, functor);
140 mask = 0; max_digit = 0;
141 for (it = first; it != cut; ++it) {
142 if ((mask | functor(*it)) != ~0) {
148 radixIntroSort(first, cut, functor, 1 << max_digit);
150 mask = ~0; max_digit = 0;
151 for (it = cut; it != last; ++it) {
152 if (mask & functor(*it)) {
157 radixIntroSort(cut, last, functor, 1 << max_digit);
160 template <typename Value, typename Iterator, typename Functor>
161 void radixUnsignedSort(Iterator first, Iterator last, Functor functor) {
167 for (it = first; it != last; ++it) {
168 if (mask & functor(*it)) {
173 radixIntroSort(first, last, functor, 1 << max_digit);
176 namespace _radix_sort_bits {
178 template <typename Value,
179 bool sign = std::numeric_limits<Value>::is_signed >
180 struct RadixSortSelector {
181 template <typename Iterator, typename Functor>
182 static void sort(Iterator first, Iterator last, Functor functor) {
183 radixSignedSort<Value>(first, last, functor);
187 template <typename Value>
188 struct RadixSortSelector<Value, false> {
189 template <typename Iterator, typename Functor>
190 static void sort(Iterator first, Iterator last, Functor functor) {
191 radixUnsignedSort<Value>(first, last, functor);
199 /// \brief Sorts the stl compatible range into ascending order.
201 /// The \c radixSort sorts the stl compatible range into ascending order.
202 /// The radix sort algorithm can sort the items which mapped to an
203 /// integer by the adaptable unary function \c functor and the order
204 /// will be ascending by these mapped values. As function specialization
205 /// there is possible to use a normal function as the functor object
206 /// or if the functor is not given it will use an identity function instead.
208 /// This implemented radix sort is a special quick sort which pivot value
209 /// is choosen to partite the items on the next bit. This way, let be
210 /// \c c the maximal capacity and \c n the number of the items in
211 /// the container, the time complexity of the algorithm
212 /// \f$ O(\log(c)n) \f$ and the additional space complexity is
213 /// \f$ O(\log(c)) \f$.
215 /// \param first The begin of the given range.
216 /// \param last The end of the given range.
217 /// \param functor An adaptible unary function or a normal function which
218 /// maps the items to any integer type which can be wheter signed or
220 template <typename Iterator, typename Functor>
221 void radixSort(Iterator first, Iterator last, Functor functor) {
222 using namespace _radix_sort_bits;
223 typedef typename Functor::result_type Value;
224 RadixSortSelector<Value>::sort(first, last, functor);
227 template <typename Iterator, typename Value, typename Key>
228 void radixSort(Iterator first, Iterator last, Value (*functor)(Key)) {
229 using namespace _radix_sort_bits;
230 RadixSortSelector<Value>::sort(first, last, functor);
233 template <typename Iterator, typename Value, typename Key>
234 void radixSort(Iterator first, Iterator last, Value& (*functor)(Key)) {
235 using namespace _radix_sort_bits;
236 RadixSortSelector<Value>::sort(first, last, functor);
239 template <typename Iterator, typename Value, typename Key>
240 void radixSort(Iterator first, Iterator last, Value (*functor)(Key&)) {
241 using namespace _radix_sort_bits;
242 RadixSortSelector<Value>::sort(first, last, functor);
245 template <typename Iterator, typename Value, typename Key>
246 void radixSort(Iterator first, Iterator last, Value& (*functor)(Key&)) {
247 using namespace _radix_sort_bits;
248 RadixSortSelector<Value>::sort(first, last, functor);
251 template <typename Iterator>
252 void radixSort(Iterator first, Iterator last) {
253 using namespace _radix_sort_bits;
254 typedef typename std::iterator_traits<Iterator>::value_type Value;
255 RadixSortSelector<Value>::sort(first, last, Identity<Value>());
258 template <typename Value>
259 unsigned char valueByte(Value value, int byte) {
260 return value >> (std::numeric_limits<unsigned char>::digits * byte);
263 template <typename Functor, typename Key>
264 void counterIntroSort(Key *first, Key *last, Key *target,
265 int byte, Functor functor) {
267 unsigned(std::numeric_limits<unsigned char>::max()) + 1;
268 std::vector<int> counter(size);
269 for (int i = 0; i < size; ++i) {
273 while (first != last) {
274 ++counter[valueByte(functor(*first), byte)];
278 for (int i = 0; i < size; ++i) {
284 target[counter[valueByte(functor(*it), byte)]++] = *it;
289 template <typename Functor, typename Key>
290 void signedCounterIntroSort(Key *first, Key *last, Key *target,
291 int byte, Functor functor) {
293 unsigned(std::numeric_limits<unsigned char>::max()) + 1;
294 std::vector<int> counter(size);
295 for (int i = 0; i < size; ++i) {
299 while (first != last) {
300 counter[valueByte(functor(*first), byte)]++;
304 for (int i = size / 2; i < size; ++i) {
309 for (int i = 0; i < size / 2; ++i) {
315 target[counter[valueByte(functor(*it), byte)]++] = *it;
321 template <typename Value, typename Iterator, typename Functor>
322 void counterSignedSort(Iterator first, Iterator last, Functor functor) {
323 if (first == last) return;
324 typedef typename std::iterator_traits<Iterator>::value_type Key;
325 typedef std::allocator<Key> Allocator;
328 int length = std::distance(first, last);
329 Key* buffer = allocator.allocate(2 * length);
332 std::copy(first, last, buffer);
333 for (int i = 0; i < int(sizeof(Value)) - 1; ++i) {
335 counterIntroSort(buffer, buffer + length, buffer + length,
338 counterIntroSort(buffer + length, buffer + 2 * length, buffer,
344 signedCounterIntroSort(buffer, buffer + length, buffer + length,
345 sizeof(Value) - 1, functor);
346 std::copy(buffer + length, buffer + 2 * length, first);
348 signedCounterIntroSort(buffer + length, buffer + 2 * length, buffer,
349 sizeof(Value) - 1, functor);
350 std::copy(buffer, buffer + length, first);
353 allocator.deallocate(buffer, 2 * length);
356 allocator.deallocate(buffer, 2 * length);
359 template <typename Value, typename Iterator, typename Functor>
360 void counterUnsignedSort(Iterator first, Iterator last, Functor functor) {
361 if (first == last) return;
362 typedef typename std::iterator_traits<Iterator>::value_type Key;
363 typedef std::allocator<Key> Allocator;
366 int length = std::distance(first, last);
367 Key *buffer = allocator.allocate(2 * length);
370 std::copy(first, last, buffer);
371 for (int i = 0; i < int(sizeof(Value)); ++i) {
373 counterIntroSort(buffer, buffer + length,
374 buffer + length, i, functor);
376 counterIntroSort(buffer + length, buffer + 2 * length,
382 std::copy(buffer, buffer + length, first);
384 std::copy(buffer + length, buffer + 2 * length, first);
387 allocator.deallocate(buffer, 2 * length);
390 allocator.deallocate(buffer, 2 * length);
393 namespace _radix_sort_bits {
395 template <typename Value,
396 bool sign = std::numeric_limits<Value>::is_signed >
397 struct CounterSortSelector {
398 template <typename Iterator, typename Functor>
399 static void sort(Iterator first, Iterator last, Functor functor) {
400 counterSignedSort<Value>(first, last, functor);
404 template <typename Value>
405 struct CounterSortSelector<Value, false> {
406 template <typename Iterator, typename Functor>
407 static void sort(Iterator first, Iterator last, Functor functor) {
408 counterUnsignedSort<Value>(first, last, functor);
416 /// \brief Sorts stable the stl compatible range into ascending order.
418 /// The \c counterSort sorts the stl compatible range into ascending order.
419 /// The counter sort algorithm can sort the items which mapped to an
420 /// integer by the adaptable unary function \c functor and the order
421 /// will be ascending by these mapped values. As function specialization
422 /// there is possible to use a normal function as the functor object
423 /// or if the functor is not given it will use an identity function instead.
425 /// This implemented counter sort use a radix forward sort on the bytes of
426 /// the integer. The algorithm can sort the items on a given byte.
427 /// First time it counts how many times occurs a byte value in the container.
428 /// By the occurence number it is possible to copy the container
429 /// in the right order in \c O(n) time. The algorithm sorts the container
430 /// by each bytes in forward direction which sorts the container by the
431 /// whole value. This way, let be \c c the maximal capacity of the integer
432 /// type and \c n the number of the items in
433 /// the container, the time complexity of the algorithm \f$ O(\log(c)n) \f$
434 /// and the additional space complexity is \f$ O(n) \f$.
436 /// This sorting algorithm is stable so the order of two equal element
437 /// stay in the same order.
439 /// \param first The begin of the given range.
440 /// \param last The end of the given range.
441 /// \param functor An adaptible unary function or a normal function which
442 /// maps the items to any integer type which can be wheter signed or
444 template <typename Iterator, typename Functor>
445 void counterSort(Iterator first, Iterator last, Functor functor) {
446 using namespace _radix_sort_bits;
447 typedef typename Functor::result_type Value;
448 CounterSortSelector<Value>::sort(first, last, functor);
451 template <typename Iterator, typename Value, typename Key>
452 void counterSort(Iterator first, Iterator last, Value (*functor)(Key)) {
453 using namespace _radix_sort_bits;
454 CounterSortSelector<Value>::sort(first, last, functor);
457 template <typename Iterator, typename Value, typename Key>
458 void counterSort(Iterator first, Iterator last, Value& (*functor)(Key)) {
459 using namespace _radix_sort_bits;
460 CounterSortSelector<Value>::sort(first, last, functor);
463 template <typename Iterator, typename Value, typename Key>
464 void counterSort(Iterator first, Iterator last, Value (*functor)(Key&)) {
465 using namespace _radix_sort_bits;
466 CounterSortSelector<Value>::sort(first, last, functor);
469 template <typename Iterator, typename Value, typename Key>
470 void counterSort(Iterator first, Iterator last, Value& (*functor)(Key&)) {
471 using namespace _radix_sort_bits;
472 CounterSortSelector<Value>::sort(first, last, functor);
475 template <typename Iterator>
476 void counterSort(Iterator first, Iterator last) {
477 using namespace _radix_sort_bits;
478 typedef typename std::iterator_traits<Iterator>::value_type Value;
479 CounterSortSelector<Value>::sort(first, last, Identity<Value>());