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boost_algorithm/test/indirect_sort_test.cpp
2023-06-14 18:30:08 -07:00

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3.3 KiB
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/*
Copyright (c) Marshall Clow 2011-2012.
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
For more information, see http://www.boost.org
*/
#include <boost/config.hpp>
#include <boost/algorithm/indirect_sort.hpp>
#include <boost/algorithm/apply_permutation.hpp>
#include <boost/algorithm/cxx11/is_sorted.hpp>
#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp>
#include <iostream>
#include <string>
#include <vector>
#include <list>
typedef std::vector<size_t> 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.
bool isa_permutation(Permutation p, size_t N) {
if (p.size() != N) return false;
// Sort the permutation, and ensure that each value appears exactly once.
std::sort(p.begin(), p.end());
for (size_t i = 0; i < N; ++i)
if (p[i] != i) return false;
return true;
}
template <typename Iter,
typename Comp = typename std::less<typename std::iterator_traits<Iter>::value_type> >
struct indirect_comp {
indirect_comp (Iter it, Comp c = Comp())
: iter_(it), comp_(c) {}
bool operator ()(size_t a, size_t b) const { return comp_(iter_[a], iter_[b]);}
Iter iter_;
Comp comp_;
};
template <typename Iter>
void test_one_sort(Iter first, Iter last) {
Permutation perm = boost::algorithm::indirect_sort(first, last);
BOOST_CHECK (isa_permutation(perm, std::distance(first, 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);
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_sort(Iter first, Iter last, Comp comp) {
Permutation perm = boost::algorithm::indirect_sort(first, last, comp);
BOOST_CHECK (isa_permutation(perm, std::distance(first, last)));
BOOST_CHECK (boost::algorithm::is_sorted(perm.begin(), perm.end(),
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);
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_sort () {
BOOST_CXX14_CONSTEXPR 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) {
test_one_sort(first, first + i);
test_one_sort(first, first + i, std::greater<int>());
// test with constant inputs
test_one_sort(cFirst, cFirst + i);
test_one_sort(cFirst, cFirst + i, std::greater<int>());
}
// make sure we work with iterators as well as pointers
std::vector<int> v(first, first + sz);
test_one_sort(v.begin(), v.end());
test_one_sort(v.begin(), v.end(), std::greater<int>());
}
BOOST_AUTO_TEST_CASE( test_main )
{
test_sort ();
}