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Add more tests

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Marshall Clow
2023-06-20 20:01:38 -07:00
parent 814f8a5c05
commit 3ae9ee2f92
2 changed files with 272 additions and 5 deletions
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14
doc/indirect_sort.qbk
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@ -34,7 +34,7 @@ Or maybe you don't need the elements to actually be sorted - you just want to tr
```
Assume that instead of an "array of structures", you have a "struct of arrays"
Assume that instead of an "array of structures", you have a "struct of arrays".
```
struct AType {
Type0 key;
@ -70,12 +70,20 @@ Sorting the first one is easy, because each set of fields (`key`, `value1`, `val
The function `indirect_sort` returns a `vector<size_t>` containing the permutation necessary to put the input sequence into a sorted order. One version uses `std::less` to do the comparisons; the other lets the caller pass predicate to do the comparisons.
There is also a variant called `indirect_stable_sort`; it bears the same relation to `indirect_sort` that `std::stable_sort` does to `std::sort`.
```
template <typename RAIterator>
std::vector<size_t> indirect_sort (RAIterator first, RAIterator last);
template <typename RAIterator, typename BinaryPredicate>
std::vector<size_t> indirect_sort (RAIterator first, RAIterator last, BinaryPredicate pred);
template <typename RAIterator>
std::vector<size_t> indirect_stable_sort (RAIterator first, RAIterator last);
template <typename RAIterator, typename BinaryPredicate>
std::vector<size_t> indirect_stable_sort (RAIterator first, RAIterator last, BinaryPredicate pred);
```
[heading Examples]
@ -86,12 +94,14 @@ std::vector<size_t> indirect_sort (RAIterator first, RAIterator last, BinaryPred
[heading Complexity]
Both of the variants of `indirect_sort` run in ['O(N lg N)] time; they are not more (or less) efficient than `std::sort`. There is an extra layer of indirection on each comparison, but all off the swaps are done on values of type `size_t`
Both of the variants of `indirect_sort` run in ['O(N lg N)] time; they are not more (or less) efficient than `std::sort`. There is an extra layer of indirection on each comparison, but all of the swaps are done on values of type `size_t`
[heading Exception Safety]
[heading Notes]
In numpy, this algorithm is known as `argsort`.
[endsect]
[/ File indirect_sort.qbk

263
test/indirect_sort_test.cpp
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@ -11,6 +11,7 @@
#include <boost/algorithm/indirect_sort.hpp>
#include <boost/algorithm/apply_permutation.hpp>
#include <boost/algorithm/cxx11/is_sorted.hpp>
#include <boost/algorithm/cxx11/all_of.hpp>
#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp>
@ -20,7 +21,7 @@
#include <vector>
#include <list>
typedef std::vector<size_t> Permutation;
using boost::algorithm::Permutation;
// A permutation of size N is a sequence of values in the range [0..N)
// such that no value appears more than once in the permutation.
@ -46,6 +47,9 @@ struct indirect_comp {
Comp comp_;
};
//// =======================
//// ==== indirect_sort ====
//// =======================
template <typename Iter>
void test_one_sort(Iter first, Iter last) {
Permutation perm = boost::algorithm::indirect_sort(first, last);
@ -53,7 +57,8 @@ void test_one_sort(Iter first, Iter last) {
BOOST_CHECK (boost::algorithm::is_sorted(perm.begin(), perm.end(), indirect_comp<Iter>(first)));
// Make a copy of the data, apply the permutation, and ensure that it is sorted.
std::vector<typename std::iterator_traits<Iter>::value_type> v(first, last);
typedef std::vector<typename std::iterator_traits<Iter>::value_type> Vector;
Vector v(first, last);
boost::algorithm::apply_permutation(v.begin(), v.end(), perm.begin(), perm.end());
BOOST_CHECK (boost::algorithm::is_sorted(v.begin(), v.end()));
}
@ -66,7 +71,8 @@ void test_one_sort(Iter first, Iter last, Comp comp) {
indirect_comp<Iter, Comp>(first, comp)));
// Make a copy of the data, apply the permutation, and ensure that it is sorted.
std::vector<typename std::iterator_traits<Iter>::value_type> v(first, last);
typedef std::vector<typename std::iterator_traits<Iter>::value_type> Vector;
Vector v(first, last);
boost::algorithm::apply_permutation(v.begin(), v.end(), perm.begin(), perm.end());
BOOST_CHECK (boost::algorithm::is_sorted(v.begin(), v.end(), comp));
}
@ -93,8 +99,259 @@ void test_sort () {
test_one_sort(v.begin(), v.end());
test_one_sort(v.begin(), v.end(), std::greater<int>());
}
//// ==============================
//// ==== indirect_stable_sort ====
//// ==============================
template <typename T1, typename T2>
struct MyPair {
MyPair () {}
MyPair (const T1 &t1, const T2 &t2)
: first(t1), second(t2) {}
T1 first;
T2 second;
};
template <typename T1, typename T2>
bool operator < (const MyPair<T1, T2>& lhs, const MyPair<T1, T2>& rhs) {
return lhs.first < rhs.first; // compare only the first elements
}
template <typename T1, typename T2>
bool MyGreater (const MyPair<T1, T2>& lhs, const MyPair<T1, T2>& rhs) {
return lhs.first > rhs.first; // compare only the first elements
}
template <typename Iter>
void test_one_stable_sort(Iter first, Iter last) {
Permutation perm = boost::algorithm::indirect_stable_sort(first, last);
BOOST_CHECK (is_a_permutation(perm, std::distance(first, last)));
BOOST_CHECK (boost::algorithm::is_sorted(perm.begin(), perm.end(), indirect_comp<Iter>(first)));
if (first != last) {
Iter iFirst = first;
Iter iSecond = first; ++iSecond;
while (iSecond != last) {
if (iFirst->first == iSecond->first)
BOOST_CHECK(iFirst->second < iSecond->second);
++iFirst;
++iSecond;
}
}
// Make a copy of the data, apply the permutation, and ensure that it is sorted.
typedef std::vector<typename std::iterator_traits<Iter>::value_type> Vector;
Vector v(first, last);
boost::algorithm::apply_permutation(v.begin(), v.end(), perm.begin(), perm.end());
BOOST_CHECK (boost::algorithm::is_sorted(v.begin(), v.end()));
}
template <typename Iter, typename Comp>
void test_one_stable_sort(Iter first, Iter last, Comp comp) {
Permutation perm = boost::algorithm::indirect_stable_sort(first, last, comp);
BOOST_CHECK (is_a_permutation(perm, std::distance(first, last)));
BOOST_CHECK (boost::algorithm::is_sorted(perm.begin(), perm.end(), indirect_comp<Iter, Comp>(first, comp)));
if (first != last) {
Iter iFirst = first;
Iter iSecond = first; ++iSecond;
while (iSecond != last) {
if (iFirst->first == iSecond->first)
BOOST_CHECK(iFirst->second < iSecond->second);
++iFirst;
++iSecond;
}
}
// Make a copy of the data, apply the permutation, and ensure that it is sorted.
typedef std::vector<typename std::iterator_traits<Iter>::value_type> Vector;
Vector v(first, last);
boost::algorithm::apply_permutation(v.begin(), v.end(), perm.begin(), perm.end());
BOOST_CHECK (boost::algorithm::is_sorted(v.begin(), v.end(), comp));
}
void test_stable_sort () {
typedef MyPair<int, long> Pair;
const int sz = 10;
Pair vals[sz];
for (int i = 0; i < sz; ++i) {
vals[i].first = 100 - (i >> 1);
vals[i].second = i;
}
Pair *first = &vals[0];
Pair const *cFirst = &vals[0];
// Test subsets
for (size_t i = 0; i <= sz; ++i) {
test_one_stable_sort(first, first + i);
test_one_stable_sort(first, first + i, MyGreater<int, long>);
// test with constant inputs
test_one_sort(cFirst, cFirst + i);
test_one_sort(cFirst, cFirst + i, MyGreater<int, long>);
}
}
//// ===============================
//// ==== indirect_partial_sort ====
//// ===============================
template <typename Iter>
void test_one_partial_sort(Iter first, Iter middle, Iter last) {
const size_t middleIdx = std::distance(first, middle);
Permutation perm = boost::algorithm::indirect_partial_sort(first, middle, last);
BOOST_CHECK (is_a_permutation(perm, std::distance(first, last)));
BOOST_CHECK (boost::algorithm::is_sorted(perm.begin(), perm.begin() + middleIdx, indirect_comp<Iter>(first)));
// Make a copy of the data, apply the permutation, and ensure that it is sorted.
typedef std::vector<typename std::iterator_traits<Iter>::value_type> Vector;
Vector v(first, last);
boost::algorithm::apply_permutation(v.begin(), v.end(), perm.begin(), perm.end());
BOOST_CHECK (boost::algorithm::is_sorted(v.begin(), v.begin() + middleIdx));
// Make sure that [middle, end) are all "greater" than the sorted part
if (middleIdx > 0) {
typename Vector::iterator lastSorted = v.begin() + middleIdx - 1;
for (typename Vector::iterator it = v.begin () + middleIdx; it != v.end(); ++it)
BOOST_CHECK(*lastSorted < *it);
}
}
template <typename Iter, typename Comp>
void test_one_partial_sort(Iter first, Iter middle, Iter last, Comp comp) {
const size_t middleIdx = std::distance(first, middle);
Permutation perm = boost::algorithm::indirect_partial_sort(first, middle, last, comp);
BOOST_CHECK (is_a_permutation(perm, std::distance(first, last)));
BOOST_CHECK (boost::algorithm::is_sorted(perm.begin(), perm.begin() + middleIdx,
indirect_comp<Iter, Comp>(first, comp)));
// Make a copy of the data, apply the permutation, and ensure that it is sorted.
typedef std::vector<typename std::iterator_traits<Iter>::value_type> Vector;
Vector v(first, last);
boost::algorithm::apply_permutation(v.begin(), v.end(), perm.begin(), perm.end());
BOOST_CHECK (boost::algorithm::is_sorted(v.begin(), v.begin() + middleIdx, comp));
// Make sure that [middle, end) are all "greater" than the sorted part
if (middleIdx > 0) {
typename Vector::iterator lastSorted = v.begin() + middleIdx - 1;
for (typename Vector::iterator it = v.begin () + middleIdx; it != v.end(); ++it)
BOOST_CHECK(comp(*lastSorted, *it));
}
}
void test_partial_sort () {
int num[] = { 1,3,5,7,9, 2, 4, 6, 8, 10 };
const int sz = sizeof (num)/sizeof(num[0]);
int *first = &num[0];
int const *cFirst = &num[0];
// Test subsets
for (size_t i = 0; i <= sz; ++i) {
for (size_t j = 0; j < i; ++j) {
test_one_partial_sort(first, first + j, first + i);
test_one_partial_sort(first, first + j, first + i, std::greater<int>());
// test with constant inputs
test_one_partial_sort(cFirst, cFirst + j, cFirst + i);
test_one_partial_sort(cFirst, cFirst + j, cFirst + i, std::greater<int>());
}
}
// make sure we work with iterators as well as pointers
std::vector<int> v(first, first + sz);
test_one_partial_sort(v.begin(), v.begin() + (sz / 2), v.end());
test_one_partial_sort(v.begin(), v.begin() + (sz / 2), v.end(), std::greater<int>());
}
//// ===================================
//// ==== indirect_nth_element_sort ====
//// ===================================
template <typename Iter>
void test_one_nth_element(Iter first, Iter nth, Iter last) {
const size_t nthIdx = std::distance(first, nth);
Permutation perm = boost::algorithm::indirect_nth_element(first, nth, last);
BOOST_CHECK (is_a_permutation(perm, std::distance(first, last)));
for (size_t i = 0; i < nthIdx; ++i)
BOOST_CHECK(!(first[perm[nthIdx]] < first[perm[i]])); // all items before the nth element are <= the nth element
for (size_t i = nthIdx; i < std::distance(first, last); ++i)
BOOST_CHECK(!(first[perm[i]] < first[perm[nthIdx]])); // all items before the nth element are >= the nth element
// Make a copy of the data, apply the permutation, and ensure that the result is correct.
typedef std::vector<typename std::iterator_traits<Iter>::value_type> Vector;
Vector v(first, last);
boost::algorithm::apply_permutation(v.begin(), v.end(), perm.begin(), perm.end());
for (size_t i = 0; i < nthIdx; ++i)
BOOST_CHECK(!(v[nthIdx] < v[i])); // all items before the nth element are <= the nth element
for (size_t i = nthIdx; i < v.size(); ++i)
BOOST_CHECK(!(v[i] < v[nthIdx])); // all items before the nth element are >= the nth element
}
template <typename Iter, typename Comp>
void test_one_nth_element(Iter first, Iter nth, Iter last, Comp comp) {
const size_t nthIdx = std::distance(first, nth);
Permutation perm = boost::algorithm::indirect_nth_element(first, nth, last, comp);
BOOST_CHECK (is_a_permutation(perm, std::distance(first, last)));
for (size_t i = 0; i < nthIdx; ++i)
BOOST_CHECK(!comp(first[perm[nthIdx]], first[perm[i]])); // all items before the nth element are <= the nth element
for (size_t i = nthIdx; i < std::distance(first, last); ++i)
BOOST_CHECK(!comp(first[perm[i]], first[perm[nthIdx]])); // all items before the nth element are >= the nth element
// Make a copy of the data, apply the permutation, and ensure that the result is correct.
typedef std::vector<typename std::iterator_traits<Iter>::value_type> Vector;
Vector v(first, last);
boost::algorithm::apply_permutation(v.begin(), v.end(), perm.begin(), perm.end());
for (size_t i = 0; i < nthIdx; ++i)
BOOST_CHECK(!comp(v[nthIdx], v[i])); // all items before the nth element are <= the nth element
for (size_t i = nthIdx; i < v.size(); ++i)
BOOST_CHECK(!comp(v[i], v[nthIdx])); // all items before the nth element are >= the nth element
}
void test_nth_element () {
int num[] = { 1, 3, 5, 7, 9, 2, 4, 6, 8, 10, 1, 2, 3, 4, 5 };
const int sz = sizeof (num)/sizeof(num[0]);
int *first = &num[0];
int const *cFirst = &num[0];
// Test subsets
for (size_t i = 0; i <= sz; ++i) {
for (size_t j = 0; j < i; ++j) {
test_one_nth_element(first, first + j, first + i);
test_one_nth_element(first, first + j, first + i, std::greater<int>());
// test with constant inputs
test_one_nth_element(cFirst, cFirst + j, cFirst + i);
test_one_nth_element(cFirst, cFirst + j, cFirst + i, std::greater<int>());
}
}
// make sure we work with iterators as well as pointers
std::vector<int> v(first, first + sz);
test_one_nth_element(v.begin(), v.begin() + (sz / 2), v.end());
test_one_nth_element(v.begin(), v.begin() + (sz / 2), v.end(), std::greater<int>());
}
BOOST_AUTO_TEST_CASE( test_main )
{
test_sort ();
test_stable_sort ();
test_partial_sort ();
test_nth_element ();
}