# HG changeset patch
# User Balazs Dezso <deba@inf.elte.hu>
# Date 1224280518 -7200
# Node ID 4f7224faf3bd0bf460965b685cd503a838251df9
# Parent 6dbd5184c6a99e936a7de899e64c114e30c0f94f
Porting radix sorts from SVN #3509
diff -r 6dbd5184c6a9 -r 4f7224faf3bd lemon/Makefile.am
--- a/lemon/Makefile.am Sun Oct 12 19:35:48 2008 +0100
+++ b/lemon/Makefile.am Fri Oct 17 23:55:18 2008 +0200
@@ -36,6 +36,7 @@
lemon/maps.h \
lemon/math.h \
lemon/path.h \
+ lemon/radix_sort.h \
lemon/random.h \
lemon/smart_graph.h \
lemon/time_measure.h \
diff -r 6dbd5184c6a9 -r 4f7224faf3bd lemon/radix_sort.h
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/lemon/radix_sort.h Fri Oct 17 23:55:18 2008 +0200
@@ -0,0 +1,484 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2008
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#ifndef RADIX_SORT_H
+#define RADIX_SORT_H
+
+/// \ingroup auxalg
+/// \file
+/// \brief Radix sort
+///
+/// Linear time sorting algorithms
+
+#include <vector>
+#include <limits>
+#include <iterator>
+#include <algorithm>
+
+namespace lemon {
+
+ namespace _radix_sort_bits {
+
+ template <typename Value>
+ struct Identity {
+ const Value& operator()(const Value& val) {
+ return val;
+ }
+ };
+
+
+ template <typename Value, typename Iterator, typename Functor>
+ Iterator radixSortPartition(Iterator first, Iterator last,
+ Functor functor, Value mask) {
+ while (first != last && !(functor(*first) & mask)) {
+ ++first;
+ }
+ if (first == last) {
+ return first;
+ }
+ --last;
+ while (first != last && (functor(*last) & mask)) {
+ --last;
+ }
+ if (first == last) {
+ return first;
+ }
+ std::iter_swap(first, last);
+ ++first;
+ if (!(first < last)) {
+ return first;
+ }
+ while (true) {
+ while (!(functor(*first) & mask)) {
+ ++first;
+ }
+ --last;
+ while (functor(*last) & mask) {
+ --last;
+ }
+ if (!(first < last)) {
+ return first;
+ }
+ std::iter_swap(first, last);
+ ++first;
+ }
+ }
+
+ template <typename Iterator, typename Functor>
+ Iterator radixSortSignPartition(Iterator first, Iterator last,
+ Functor functor) {
+ while (first != last && functor(*first) < 0) {
+ ++first;
+ }
+ if (first == last) {
+ return first;
+ }
+ --last;
+ while (first != last && functor(*last) >= 0) {
+ --last;
+ }
+ if (first == last) {
+ return first;
+ }
+ std::iter_swap(first, last);
+ ++first;
+ if (!(first < last)) {
+ return first;
+ }
+ while (true) {
+ while (functor(*first) < 0) {
+ ++first;
+ }
+ --last;
+ while (functor(*last) >= 0) {
+ --last;
+ }
+ if (!(first < last)) {
+ return first;
+ }
+ std::iter_swap(first, last);
+ ++first;
+ }
+ }
+
+ template <typename Value, typename Iterator, typename Functor>
+ void radixIntroSort(Iterator first, Iterator last,
+ Functor functor, Value mask) {
+ while (mask != 0 && last - first > 1) {
+ Iterator cut = radixSortPartition(first, last, functor, mask);
+ mask >>= 1;
+ radixIntroSort(first, cut, functor, mask);
+ first = cut;
+ }
+ }
+
+ template <typename Value, typename Iterator, typename Functor>
+ void radixSignedSort(Iterator first, Iterator last, Functor functor) {
+
+ Iterator cut = radixSortSignPartition(first, last, functor);
+
+ Value mask;
+ int max_digit;
+ Iterator it;
+
+ mask = ~0; max_digit = 0;
+ for (it = first; it != cut; ++it) {
+ while ((mask & functor(*it)) != mask) {
+ ++max_digit;
+ mask <<= 1;
+ }
+ }
+ radixIntroSort(first, cut, functor, 1 << max_digit);
+
+ mask = 0; max_digit = 0;
+ for (it = cut; it != last; ++it) {
+ while ((mask | functor(*it)) != mask) {
+ ++max_digit;
+ mask <<= 1; mask |= 1;
+ }
+ }
+ radixIntroSort(cut, last, functor, 1 << max_digit);
+ }
+
+ template <typename Value, typename Iterator, typename Functor>
+ void radixUnsignedSort(Iterator first, Iterator last, Functor functor) {
+
+ Value mask = 0;
+ int max_digit = 0;
+
+ Iterator it;
+ for (it = first; it != last; ++it) {
+ while ((mask | functor(*it)) != mask) {
+ ++max_digit;
+ mask <<= 1; mask |= 1;
+ }
+ }
+ radixIntroSort(first, last, functor, 1 << max_digit);
+ }
+
+
+ template <typename Value,
+ bool sign = std::numeric_limits<Value>::is_signed >
+ struct RadixSortSelector {
+ template <typename Iterator, typename Functor>
+ static void sort(Iterator first, Iterator last, Functor functor) {
+ radixSignedSort<Value>(first, last, functor);
+ }
+ };
+
+ template <typename Value>
+ struct RadixSortSelector<Value, false> {
+ template <typename Iterator, typename Functor>
+ static void sort(Iterator first, Iterator last, Functor functor) {
+ radixUnsignedSort<Value>(first, last, functor);
+ }
+ };
+
+ }
+
+ /// \ingroup auxalg
+ ///
+ /// \brief Sorts the STL compatible range into ascending order.
+ ///
+ /// The \c radixSort sorts the STL compatible range into ascending
+ /// order. The radix sort algorithm can sort the items which mapped
+ /// to an integer with an adaptable unary function \c functor and the
+ /// order will be ascending by these mapped values. As function
+ /// specialization it is possible to use a normal function instead
+ /// of the functor object or if the functor is not given it will use
+ /// an identity function instead.
+ ///
+ /// This implemented radix sort is a special quick sort which pivot
+ /// value is choosen to partite the items on the next
+ /// bit. Therefore, let be \c c the maximal capacity and \c n the
+ /// number of the items in the container, the time complexity of the
+ /// algorithm is \f$ O(\log(c)n) \f$ and the additional space
+ /// complexity is \f$ O(\log(c)) \f$.
+ ///
+ /// \param first The begin of the given range.
+ /// \param last The end of the given range.
+ /// \param functor An adaptible unary function or a normal function
+ /// which maps the items to any integer type which can be either
+ /// signed or unsigned.
+ template <typename Iterator, typename Functor>
+ void radixSort(Iterator first, Iterator last, Functor functor) {
+ using namespace _radix_sort_bits;
+ typedef typename Functor::result_type Value;
+ RadixSortSelector<Value>::sort(first, last, functor);
+ }
+
+ template <typename Iterator, typename Value, typename Key>
+ void radixSort(Iterator first, Iterator last, Value (*functor)(Key)) {
+ using namespace _radix_sort_bits;
+ RadixSortSelector<Value>::sort(first, last, functor);
+ }
+
+ template <typename Iterator, typename Value, typename Key>
+ void radixSort(Iterator first, Iterator last, Value& (*functor)(Key)) {
+ using namespace _radix_sort_bits;
+ RadixSortSelector<Value>::sort(first, last, functor);
+ }
+
+ template <typename Iterator, typename Value, typename Key>
+ void radixSort(Iterator first, Iterator last, Value (*functor)(Key&)) {
+ using namespace _radix_sort_bits;
+ RadixSortSelector<Value>::sort(first, last, functor);
+ }
+
+ template <typename Iterator, typename Value, typename Key>
+ void radixSort(Iterator first, Iterator last, Value& (*functor)(Key&)) {
+ using namespace _radix_sort_bits;
+ RadixSortSelector<Value>::sort(first, last, functor);
+ }
+
+ template <typename Iterator>
+ void radixSort(Iterator first, Iterator last) {
+ using namespace _radix_sort_bits;
+ typedef typename std::iterator_traits<Iterator>::value_type Value;
+ RadixSortSelector<Value>::sort(first, last, Identity<Value>());
+ }
+
+ namespace _radix_sort_bits {
+
+ template <typename Value>
+ unsigned char valueByte(Value value, int byte) {
+ return value >> (std::numeric_limits<unsigned char>::digits * byte);
+ }
+
+ template <typename Functor, typename Key>
+ void counterIntroSort(Key *first, Key *last, Key *target,
+ int byte, Functor functor) {
+ const int size =
+ unsigned(std::numeric_limits<unsigned char>::max()) + 1;
+ std::vector<int> counter(size);
+ for (int i = 0; i < size; ++i) {
+ counter[i] = 0;
+ }
+ Key *it = first;
+ while (first != last) {
+ ++counter[valueByte(functor(*first), byte)];
+ ++first;
+ }
+ int prev, num = 0;
+ for (int i = 0; i < size; ++i) {
+ prev = num;
+ num += counter[i];
+ counter[i] = prev;
+ }
+ while (it != last) {
+ target[counter[valueByte(functor(*it), byte)]++] = *it;
+ ++it;
+ }
+ }
+
+ template <typename Functor, typename Key>
+ void signedCounterIntroSort(Key *first, Key *last, Key *target,
+ int byte, Functor functor) {
+ const int size =
+ unsigned(std::numeric_limits<unsigned char>::max()) + 1;
+ std::vector<int> counter(size);
+ for (int i = 0; i < size; ++i) {
+ counter[i] = 0;
+ }
+ Key *it = first;
+ while (first != last) {
+ counter[valueByte(functor(*first), byte)]++;
+ ++first;
+ }
+ int prev, num = 0;
+ for (int i = size / 2; i < size; ++i) {
+ prev = num;
+ num += counter[i];
+ counter[i] = prev;
+ }
+ for (int i = 0; i < size / 2; ++i) {
+ prev = num;
+ num += counter[i];
+ counter[i] = prev;
+ }
+ while (it != last) {
+ target[counter[valueByte(functor(*it), byte)]++] = *it;
+ ++it;
+ }
+ }
+
+
+ template <typename Value, typename Iterator, typename Functor>
+ void counterSignedSort(Iterator first, Iterator last, Functor functor) {
+ if (first == last) return;
+ typedef typename std::iterator_traits<Iterator>::value_type Key;
+ typedef std::allocator<Key> Allocator;
+ Allocator allocator;
+
+ int length = std::distance(first, last);
+ Key* buffer = allocator.allocate(2 * length);
+ try {
+ bool dir = true;
+ std::copy(first, last, buffer);
+ for (int i = 0; i < int(sizeof(Value)) - 1; ++i) {
+ if (dir) {
+ counterIntroSort(buffer, buffer + length, buffer + length,
+ i, functor);
+ } else {
+ counterIntroSort(buffer + length, buffer + 2 * length, buffer,
+ i, functor);
+ }
+ dir = !dir;
+ }
+ if (dir) {
+ signedCounterIntroSort(buffer, buffer + length, buffer + length,
+ sizeof(Value) - 1, functor);
+ std::copy(buffer + length, buffer + 2 * length, first);
+ } else {
+ signedCounterIntroSort(buffer + length, buffer + 2 * length, buffer,
+ sizeof(Value) - 1, functor);
+ std::copy(buffer, buffer + length, first);
+ }
+ } catch (...) {
+ allocator.deallocate(buffer, 2 * length);
+ throw;
+ }
+ allocator.deallocate(buffer, 2 * length);
+ }
+
+ template <typename Value, typename Iterator, typename Functor>
+ void counterUnsignedSort(Iterator first, Iterator last, Functor functor) {
+ if (first == last) return;
+ typedef typename std::iterator_traits<Iterator>::value_type Key;
+ typedef std::allocator<Key> Allocator;
+ Allocator allocator;
+
+ int length = std::distance(first, last);
+ Key *buffer = allocator.allocate(2 * length);
+ try {
+ bool dir = true;
+ std::copy(first, last, buffer);
+ for (int i = 0; i < int(sizeof(Value)); ++i) {
+ if (dir) {
+ counterIntroSort(buffer, buffer + length,
+ buffer + length, i, functor);
+ } else {
+ counterIntroSort(buffer + length, buffer + 2 * length,
+ buffer, i, functor);
+ }
+ dir = !dir;
+ }
+ if (dir) {
+ std::copy(buffer, buffer + length, first);
+ } else {
+ std::copy(buffer + length, buffer + 2 * length, first);
+ }
+ } catch (...) {
+ allocator.deallocate(buffer, 2 * length);
+ throw;
+ }
+ allocator.deallocate(buffer, 2 * length);
+ }
+
+
+
+ template <typename Value,
+ bool sign = std::numeric_limits<Value>::is_signed >
+ struct CounterSortSelector {
+ template <typename Iterator, typename Functor>
+ static void sort(Iterator first, Iterator last, Functor functor) {
+ counterSignedSort<Value>(first, last, functor);
+ }
+ };
+
+ template <typename Value>
+ struct CounterSortSelector<Value, false> {
+ template <typename Iterator, typename Functor>
+ static void sort(Iterator first, Iterator last, Functor functor) {
+ counterUnsignedSort<Value>(first, last, functor);
+ }
+ };
+
+ }
+
+ /// \ingroup auxalg
+ ///
+ /// \brief Sorts stable the STL compatible range into ascending order.
+ ///
+ /// The \c counterSort sorts the STL compatible range into ascending
+ /// order. The counter sort algorithm can sort the items which
+ /// mapped to an integer with an adaptable unary function \c functor
+ /// and the order will be ascending by these mapped values. As
+ /// function specialization it is possible to use a normal function
+ /// instead of the functor object or if the functor is not given it
+ /// will use an identity function instead.
+ ///
+ /// The implemented counter sort use a radix forward sort on the
+ /// bytes of the integer number. The algorithm sorts the items
+ /// byte-by-byte, first it counts how many times occurs a byte value
+ /// in the containerm, and with the occurence number the container
+ /// can be copied to an other in asceding order in \c O(n) time.
+ /// Let be \c c the maximal capacity of the integer type and \c n
+ /// the number of the items in the container, the time complexity of
+ /// the algorithm is \f$ O(\log(c)n) \f$ and the additional space
+ /// complexity is \f$ O(n) \f$.
+ ///
+ /// The sorting algorithm is stable, i.e. the order of two equal
+ /// element remains the same.
+ ///
+ /// \param first The begin of the given range.
+ /// \param last The end of the given range.
+ /// \param functor An adaptible unary function or a normal function
+ /// which maps the items to any integer type which can be either
+ /// signed or unsigned.
+ template <typename Iterator, typename Functor>
+ void counterSort(Iterator first, Iterator last, Functor functor) {
+ using namespace _radix_sort_bits;
+ typedef typename Functor::result_type Value;
+ CounterSortSelector<Value>::sort(first, last, functor);
+ }
+
+ template <typename Iterator, typename Value, typename Key>
+ void counterSort(Iterator first, Iterator last, Value (*functor)(Key)) {
+ using namespace _radix_sort_bits;
+ CounterSortSelector<Value>::sort(first, last, functor);
+ }
+
+ template <typename Iterator, typename Value, typename Key>
+ void counterSort(Iterator first, Iterator last, Value& (*functor)(Key)) {
+ using namespace _radix_sort_bits;
+ CounterSortSelector<Value>::sort(first, last, functor);
+ }
+
+ template <typename Iterator, typename Value, typename Key>
+ void counterSort(Iterator first, Iterator last, Value (*functor)(Key&)) {
+ using namespace _radix_sort_bits;
+ CounterSortSelector<Value>::sort(first, last, functor);
+ }
+
+ template <typename Iterator, typename Value, typename Key>
+ void counterSort(Iterator first, Iterator last, Value& (*functor)(Key&)) {
+ using namespace _radix_sort_bits;
+ CounterSortSelector<Value>::sort(first, last, functor);
+ }
+
+ template <typename Iterator>
+ void counterSort(Iterator first, Iterator last) {
+ using namespace _radix_sort_bits;
+ typedef typename std::iterator_traits<Iterator>::value_type Value;
+ CounterSortSelector<Value>::sort(first, last, Identity<Value>());
+ }
+
+}
+
+#endif
diff -r 6dbd5184c6a9 -r 4f7224faf3bd test/CMakeLists.txt
--- a/test/CMakeLists.txt Sun Oct 12 19:35:48 2008 +0100
+++ b/test/CMakeLists.txt Fri Oct 17 23:55:18 2008 +0200
@@ -16,6 +16,7 @@
heap_test
kruskal_test
maps_test
+ radix_sort_test
random_test
path_test
time_measure_test
diff -r 6dbd5184c6a9 -r 4f7224faf3bd test/Makefile.am
--- a/test/Makefile.am Sun Oct 12 19:35:48 2008 +0100
+++ b/test/Makefile.am Fri Oct 17 23:55:18 2008 +0200
@@ -19,6 +19,7 @@
test/heap_test \
test/kruskal_test \
test/maps_test \
+ test/radix_sort_test \
test/random_test \
test/path_test \
test/test_tools_fail \
@@ -43,6 +44,7 @@
test_kruskal_test_SOURCES = test/kruskal_test.cc
test_maps_test_SOURCES = test/maps_test.cc
test_path_test_SOURCES = test/path_test.cc
+test_radix_sort_test_SOURCES = test/radix_sort_test.cc
test_random_test_SOURCES = test/random_test.cc
test_test_tools_fail_SOURCES = test/test_tools_fail.cc
test_test_tools_pass_SOURCES = test/test_tools_pass.cc
diff -r 6dbd5184c6a9 -r 4f7224faf3bd test/radix_sort_test.cc
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/radix_sort_test.cc Fri Oct 17 23:55:18 2008 +0200
@@ -0,0 +1,147 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2008
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#include <lemon/time_measure.h>
+#include <lemon/smart_graph.h>
+#include <lemon/maps.h>
+#include <lemon/radix_sort.h>
+#include <lemon/math.h>
+
+#include "test_tools.h"
+
+#include <vector>
+#include <algorithm>
+
+using namespace lemon;
+
+static const int n = 10000;
+
+struct Negate {
+ typedef int argument_type;
+ typedef int result_type;
+ int operator()(int a) { return - a; }
+};
+
+int negate(int a) { return - a; }
+
+
+void generateIntSequence(int n, std::vector<int>& data) {
+ int prime = 9973;
+ int root = 136, value = 1;
+ for (int i = 0; i < n; ++i) {
+ data.push_back(value - prime / 2);
+ value = (value * root) % prime;
+ }
+}
+
+void generateCharSequence(int n, std::vector<unsigned char>& data) {
+ int prime = 251;
+ int root = 3, value = root;
+ for (int i = 0; i < n; ++i) {
+ data.push_back(static_cast<unsigned char>(value));
+ value = (value * root) % prime;
+ }
+}
+
+void checkRadixSort() {
+ {
+ std::vector<int> data1;
+ generateIntSequence(n, data1);
+
+ std::vector<int> data2(data1);
+ std::sort(data1.begin(), data1.end());
+
+ radixSort(data2.begin(), data2.end());
+ for (int i = 0; i < n; ++i) {
+ check(data1[i] == data2[i], "Test failed");
+ }
+
+ radixSort(data2.begin(), data2.end(), Negate());
+ for (int i = 0; i < n; ++i) {
+ check(data1[i] == data2[n - 1 - i], "Test failed");
+ }
+
+ radixSort(data2.begin(), data2.end(), negate);
+ for (int i = 0; i < n; ++i) {
+ check(data1[i] == data2[n - 1 - i], "Test failed");
+ }
+
+ }
+
+ {
+ std::vector<unsigned char> data1(n);
+ generateCharSequence(n, data1);
+
+ std::vector<unsigned char> data2(data1);
+ std::sort(data1.begin(), data1.end());
+
+ radixSort(data2.begin(), data2.end());
+ for (int i = 0; i < n; ++i) {
+ check(data1[i] == data2[i], "Test failed");
+ }
+
+ }
+}
+
+
+void checkCounterSort() {
+ {
+ std::vector<int> data1;
+ generateIntSequence(n, data1);
+
+ std::vector<int> data2(data1);
+ std::sort(data1.begin(), data1.end());
+
+ counterSort(data2.begin(), data2.end());
+ for (int i = 0; i < n; ++i) {
+ check(data1[i] == data2[i], "Test failed");
+ }
+
+ counterSort(data2.begin(), data2.end(), Negate());
+ for (int i = 0; i < n; ++i) {
+ check(data1[i] == data2[n - 1 - i], "Test failed");
+ }
+
+ counterSort(data2.begin(), data2.end(), negate);
+ for (int i = 0; i < n; ++i) {
+ check(data1[i] == data2[n - 1 - i], "Test failed");
+ }
+ }
+
+ {
+ std::vector<unsigned char> data1(n);
+ generateCharSequence(n, data1);
+
+ std::vector<unsigned char> data2(data1);
+ std::sort(data1.begin(), data1.end());
+
+ radixSort(data2.begin(), data2.end());
+ for (int i = 0; i < n; ++i) {
+ check(data1[i] == data2[i], "Test failed");
+ }
+
+ }
+}
+
+int main() {
+
+ checkRadixSort();
+ checkCounterSort();
+
+ return 0;
+}