1 #include "src/3rd-party/catch.hpp"
2 #include "src/xbt/utils/iter/LazyKSubsets.hpp"
3 #include "src/xbt/utils/iter/LazyPowerset.hpp"
5 #include <unordered_map>
6 #include <unordered_set>
9 using namespace simgrid::xbt;
11 // This is used in a number of tests below
12 // to verify that counts of elements for example.
13 static unsigned integer_power(unsigned x, unsigned p)
16 for (unsigned j = 1; j <= p; j++)
21 TEST_CASE("simgrid::xbt::subsets_iterator: Iteration General Properties")
23 std::vector<int> example_vec{0, 1, 2, 3, 4, 5, 6, 7};
25 SECTION("Each element of each subset is distinct and appears half of the time")
27 for (unsigned k = 0; static_cast<size_t>(k) < example_vec.size(); k++) {
28 for (auto& subset : make_k_subsets_iter(k, example_vec)) {
29 // Each subset must have size `k`
30 REQUIRE(subset.size() == k);
32 // Each subset must be comprised only of distinct elements
33 std::unordered_set<int> elements_seen(k);
34 for (const auto& element_ptr : subset) {
35 const auto& element = *element_ptr;
36 REQUIRE(elements_seen.find(element) == elements_seen.end());
37 elements_seen.insert(element);
44 TEST_CASE("simgrid::xbt::powerset_iterator: Iteration General Properties")
46 std::vector<int> example_vec{0, 1, 2, 3, 4, 5, 6, 7};
48 SECTION("Each element of each subset is distinct and appears half of the time in all subsets iteration")
50 // Each element is expected to be found in half of the sets
51 const unsigned k = static_cast<unsigned>(example_vec.size());
52 const int expected_count = integer_power(2, k - 1);
54 std::unordered_map<int, int> element_counts(k);
56 for (auto& subset : make_powerset_iter(example_vec)) {
57 // Each subset must be comprised only of distinct elements
58 std::unordered_set<int> elements_seen(k);
59 for (const auto& element_ptr : subset) {
60 const auto& element = *element_ptr;
61 REQUIRE(elements_seen.find(element) == elements_seen.end());
62 elements_seen.insert(element);
63 element_counts[element]++;
67 for (const auto& iter : element_counts) {
68 REQUIRE(iter.second == expected_count);