Function directed_graph_test

dlib/test/directed_graph.cpp:33–445

        typename directed_graph
        >
    void directed_graph_test (
    )
    /*!
        requires
            - directed_graph is an implementation of directed_graph/directed_graph_kernel_abstract.h 
              is instantiated with int
        ensures
            - runs tests on directed_graph for compliance with the specs
    !*/
    {        
        print_spinner();

        COMPILE_TIME_ASSERT(is_directed_graph<directed_graph>::value == true);
        directed_graph a, b;
        dlib::set<unsigned long>::compare_1b_c s;

        DLIB_TEST(graph_contains_directed_cycle(a) == false);
        DLIB_TEST(graph_contains_undirected_cycle(a) == false);

        DLIB_TEST(a.number_of_nodes() == 0);

        DLIB_TEST(graph_contains_length_one_cycle(a) == false);

        a.set_number_of_nodes(5);
        DLIB_TEST(graph_contains_length_one_cycle(a) == false);
        DLIB_TEST(graph_is_connected(a) == false);
        DLIB_TEST(graph_contains_directed_cycle(a) == false);
        DLIB_TEST(graph_contains_undirected_cycle(a) == false);
        DLIB_TEST(a.number_of_nodes() == 5);

        for (int i = 0; i < 5; ++i)
        {
            a.node(i).data = i;
            DLIB_TEST(a.node(i).index() == (unsigned int)i);
        }

        a.remove_node(1);

        DLIB_TEST(a.number_of_nodes() == 4);


        // make sure that only the number with data == 1 was remove
        int count = 0;
        for (int i = 0; i < 4; ++i)
        {
            count += a.node(i).data;
            DLIB_TEST(a.node(i).number_of_children() == 0);
            DLIB_TEST(a.node(i).number_of_parents() == 0);
            DLIB_TEST(a.node(i).index() == (unsigned int)i);
        }

        DLIB_TEST(count == 9);

        DLIB_TEST(graph_contains_directed_cycle(a) == false);

        a.add_edge(1,1);
        DLIB_TEST(graph_contains_length_one_cycle(a) == true);
        DLIB_TEST(graph_contains_undirected_cycle(a) == true);