dlib C++ Library - graph.cpp

// Copyright (C) 2007 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#include <sstream>
#include <string>
#include <cstdlib>
#include <ctime>
#include <dlib/graph.h>
#include <dlib/graph_utils.h>
#include <dlib/set.h>
#include "tester.h"
// This is called an unnamed-namespace and it has the effect of making everything inside this file "private"
// so that everything you declare will have static linkage. Thus we won't have any multiply
// defined symbol errors coming out of the linker when we try to compile the test suite.
namespace 
{
 using namespace test;
 using namespace dlib;
 using namespace std;
 // Declare the logger we will use in this test. The name of the tester 
 // should start with "test."
 logger dlog("test.graph");
 template <
 typename graph
 >
 void graph_test (
 )
 /*!
 requires
 - graph is an implementation of graph/graph_kernel_abstract.h 
 is instantiated with int
 ensures
 - runs tests on graph for compliance with the specs
 !*/
 { 
 print_spinner();
 COMPILE_TIME_ASSERT(is_graph<graph>::value);
 graph a, b;
 dlib::set<unsigned long>::compare_1b_c s;
 DLIB_TEST(graph_contains_length_one_cycle(a) == false);
 DLIB_TEST(graph_contains_undirected_cycle(a) == false);
 DLIB_TEST(a.number_of_nodes() == 0);
 a.set_number_of_nodes(5);
 DLIB_TEST(graph_is_connected(a) == false);
 DLIB_TEST(graph_contains_undirected_cycle(a) == false);
 DLIB_TEST(a.number_of_nodes() == 5);
 DLIB_TEST(graph_contains_length_one_cycle(a) == false);
 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 removed
 int count = 0;
 for (int i = 0; i < 4; ++i)
 {
 count += a.node(i).data;
 DLIB_TEST(a.node(i).number_of_neighbors() == 0);
 DLIB_TEST(a.node(i).index() == (unsigned int)i);
 }
 DLIB_TEST(count == 9);
 a.add_edge(1,1);
 DLIB_TEST(graph_contains_length_one_cycle(a) == true);
 DLIB_TEST(graph_contains_undirected_cycle(a) == true);
 DLIB_TEST(a.has_edge(1,1));
 DLIB_TEST(a.node(1).number_of_neighbors() == 1);
 a.add_edge(1,3);
 DLIB_TEST(a.node(1).number_of_neighbors() == 2);
 DLIB_TEST(a.node(2).number_of_neighbors() == 0);
 DLIB_TEST(a.node(3).number_of_neighbors() == 1);
 DLIB_TEST(a.has_edge(1,1));
 DLIB_TEST(a.has_edge(1,3));
 DLIB_TEST(a.has_edge(3,1));
 DLIB_TEST(graph_contains_undirected_cycle(a) == true);
 a.remove_edge(1,1);
 DLIB_TEST(graph_contains_length_one_cycle(a) == false);
 DLIB_TEST(graph_contains_undirected_cycle(a) == false);
 DLIB_TEST(a.node(1).number_of_neighbors() == 1);
 DLIB_TEST(a.node(2).number_of_neighbors() == 0);
 DLIB_TEST(a.node(3).number_of_neighbors() == 1);
 DLIB_TEST(a.has_edge(1,1) == false);
 DLIB_TEST(a.has_edge(1,3));
 DLIB_TEST(a.has_edge(3,1));
 DLIB_TEST(graph_contains_undirected_cycle(a) == false);
 swap(a,b);
 DLIB_TEST(graph_contains_undirected_cycle(b) == false);
 DLIB_TEST(b.node(1).number_of_neighbors() == 1);
 DLIB_TEST(b.node(2).number_of_neighbors() == 0);
 DLIB_TEST(b.node(3).number_of_neighbors() == 1);
 DLIB_TEST(b.has_edge(1,1) == false);
 DLIB_TEST(b.has_edge(1,3));
 DLIB_TEST(b.has_edge(3,1));
 DLIB_TEST(graph_contains_undirected_cycle(b) == false);
 DLIB_TEST(a.number_of_nodes() == 0);
 DLIB_TEST(b.number_of_nodes() == 4);
 copy_graph_structure(b,b);
 DLIB_TEST(b.number_of_nodes() == 4);
 b.add_edge(1,2);
 DLIB_TEST(graph_contains_undirected_cycle(b) == false);
 DLIB_TEST(graph_contains_undirected_cycle(b) == false);
 b.add_edge(3,2);
 DLIB_TEST(graph_contains_undirected_cycle(b) == true);
 b.add_edge(1,1);
 DLIB_TEST(graph_is_connected(b) == false);
 b.add_edge(0,2);
 DLIB_TEST(graph_is_connected(b) == true);
 DLIB_TEST(graph_contains_undirected_cycle(b) == true);
 DLIB_TEST(a.number_of_nodes() == 0);
 for (unsigned long i = 0; i < b.number_of_nodes(); ++i)
 {
 for (unsigned long j = 0; j < b.node(i).number_of_neighbors(); ++j)
 {
 b.node(i).edge(j) = 'c';
 }
 }
 b.node(1).edge(0) = 'a';
 const unsigned long e1 = b.node(1).neighbor(0).index();
 b.node(0).edge(0) = 'n';
 const unsigned long e2 = b.node(0).neighbor(0).index();
 ostringstream sout;
 serialize(b, sout);
 istringstream sin(sout.str());
 DLIB_TEST(graph_contains_undirected_cycle(a) == false);
 a.set_number_of_nodes(10);
 deserialize(a, sin);
 DLIB_TEST(graph_contains_undirected_cycle(a) == true);
 for (unsigned long i = 0; i < a.number_of_nodes(); ++i)
 {
 for (unsigned long j = 0; j < a.node(i).number_of_neighbors(); ++j)
 {
 if ((i == 0 && a.node(i).neighbor(j).index() == e2) ||
 (i == e2 && a.node(i).neighbor(j).index() == 0) )
 {
 DLIB_TEST(a.node(i).edge(j) == 'n');
 }
 else if ((i == 1 && a.node(i).neighbor(j).index() == e1) ||
 (i == e1 && a.node(i).neighbor(j).index() == 1))
 {
 DLIB_TEST(a.node(i).edge(j) == 'a');
 }
 else 
 {
 DLIB_TEST(i != 0 || a.node(i).neighbor(j).index() != e2);
 DLIB_TEST_MSG(a.node(i).edge(j) == 'c',a.node(i).edge(j));
 }
 }
 }
 DLIB_TEST(a.number_of_nodes() == 4);
 DLIB_TEST(a.has_edge(1,2) == true);
 DLIB_TEST(a.has_edge(3,2) == true);
 DLIB_TEST(a.has_edge(1,1) == true);
 DLIB_TEST(a.has_edge(0,2) == true);
 DLIB_TEST(a.has_edge(1,3) == true);
 DLIB_TEST(a.has_edge(0,1) == false);
 DLIB_TEST(a.has_edge(0,3) == false);
 DLIB_TEST(a.has_edge(0,0) == false);
 DLIB_TEST(a.has_edge(1,0) == false);
 DLIB_TEST(a.has_edge(3,0) == false);
 for (unsigned long i = 0; i < a.number_of_nodes(); ++i)
 {
 a.node(i).data = static_cast<int>(i);
 }
 a.remove_node(2);
 DLIB_TEST(a.number_of_nodes() == 3);
 DLIB_TEST(graph_contains_undirected_cycle(a) == true);
 count = 0;
 for (unsigned long i = 0; i < a.number_of_nodes(); ++i)
 {
 if (a.node(i).data == 0)
 {
 DLIB_TEST(a.node(i).number_of_neighbors() == 0);
 }
 else if (a.node(i).data == 1)
 {
 DLIB_TEST(a.node(i).number_of_neighbors() == 2);
 }
 else if (a.node(i).data == 3)
 {
 DLIB_TEST(a.node(i).number_of_neighbors() == 1);
 }
 else
 {
 DLIB_TEST_MSG(false,"this is impossible");
 }
 for (unsigned long j = 0; j < a.number_of_nodes(); ++j)
 {
 if ((a.node(i).data == 1 && a.node(j).data == 1) || 
 (a.node(i).data == 1 && a.node(j).data == 3) ||
 (a.node(i).data == 3 && a.node(j).data == 1))
 {
 DLIB_TEST(a.has_edge(i,j) == true);
 ++count;
 }
 else
 {
 DLIB_TEST(a.has_edge(i,j) == false);
 }
 }
 }
 DLIB_TEST_MSG(count == 3,count);
 DLIB_TEST(graph_contains_undirected_cycle(a) == true);
 a.remove_edge(1,1);
 DLIB_TEST(graph_contains_undirected_cycle(a) == false);
 DLIB_TEST(b.number_of_nodes() == 4);
 b.clear();
 DLIB_TEST(b.number_of_nodes() == 0);
 a.clear();
 /*
 1 7
 | / \
 2 6 0
 \ / |
 3 /
 / \ /
 4 5
 */
 a.set_number_of_nodes(8);
 a.add_edge(1,2);
 a.add_edge(2,3);
 a.add_edge(3,4);
 a.add_edge(3,5);
 a.add_edge(3,6);
 a.add_edge(6,7);
 a.add_edge(7,0);
 a.add_edge(0,5);
 DLIB_TEST(graph_is_connected(a));
 dlib::set<dlib::set<unsigned long>::compare_1b_c>::kernel_1b_c sos;
 dlib::graph<dlib::set<unsigned long>::compare_1b_c, dlib::set<unsigned long>::compare_1b_c>::kernel_1a_c join_tree;
 unsigned long temp;
 triangulate_graph_and_find_cliques(a,sos);
 DLIB_TEST(a.number_of_nodes() == 8);
 create_join_tree(a, join_tree);
 DLIB_TEST(join_tree.number_of_nodes() == 6);
 DLIB_TEST(graph_is_connected(join_tree) == true);
 DLIB_TEST(graph_contains_undirected_cycle(join_tree) == false);
 DLIB_TEST(is_join_tree(a, join_tree));
 // check old edges
 DLIB_TEST(a.has_edge(1,2));
 DLIB_TEST(a.has_edge(2,3));
 DLIB_TEST(a.has_edge(3,4));
 DLIB_TEST(a.has_edge(3,5));
 DLIB_TEST(a.has_edge(3,6));
 DLIB_TEST(a.has_edge(6,7));
 DLIB_TEST(a.has_edge(7,0));
 DLIB_TEST(a.has_edge(0,5));
 DLIB_TEST(graph_is_connected(a));
 DLIB_TEST(sos.size() == 6);
 temp = 1; s.add(temp);
 temp = 2; s.add(temp);
 DLIB_TEST(sos.is_member(s));
 s.clear();
 temp = 2; s.add(temp);
 temp = 3; s.add(temp);
 DLIB_TEST(sos.is_member(s));
 s.clear();
 temp = 4; s.add(temp);
 temp = 3; s.add(temp);
 DLIB_TEST(sos.is_member(s));
 sos.reset();
 while (sos.move_next())
 {
 DLIB_TEST(is_clique(a, sos.element()));
 DLIB_TEST(is_maximal_clique(a, sos.element()));
 }
 }
 void test_copy()
 {
 {
 graph<int,int>::kernel_1a_c a,b;
 a.set_number_of_nodes(3);
 a.node(0).data = 1;
 a.node(1).data = 2;
 a.node(2).data = 3;
 a.add_edge(0,1);
 a.add_edge(0,2);
 edge(a,0,1) = 4;
 edge(a,0,2) = 5;
 a.add_edge(0,0);
 edge(a,0,0) = 9;
 copy_graph(a, b);
 DLIB_TEST(b.number_of_nodes() == 3);
 DLIB_TEST(b.node(0).data == 1);
 DLIB_TEST(b.node(1).data == 2);
 DLIB_TEST(b.node(2).data == 3);
 DLIB_TEST(edge(b,0,1) == 4);
 DLIB_TEST(edge(b,0,2) == 5);
 DLIB_TEST(edge(b,0,0) == 9);
 }
 {
 graph<int,int>::kernel_1a_c a,b;
 a.set_number_of_nodes(4);
 a.node(0).data = 1;
 a.node(1).data = 2;
 a.node(2).data = 3;
 a.node(3).data = 8;
 a.add_edge(0,1);
 a.add_edge(0,2);
 a.add_edge(2,3);
 edge(a,0,1) = 4;
 edge(a,0,2) = 5;
 edge(a,2,3) = 6;
 copy_graph(a, b);
 DLIB_TEST(b.number_of_nodes() == 4);
 DLIB_TEST(b.node(0).data == 1);
 DLIB_TEST(b.node(1).data == 2);
 DLIB_TEST(b.node(2).data == 3);
 DLIB_TEST(b.node(3).data == 8);
 DLIB_TEST(edge(b,0,1) == 4);
 DLIB_TEST(edge(b,0,2) == 5);
 DLIB_TEST(edge(b,2,3) == 6);
 }
 }
 class graph_tester : public tester
 {
 /*!
 WHAT THIS OBJECT REPRESENTS
 This object represents a test for the graph object. When it is constructed
 it adds itself into the testing framework. The command line switch is
 specified as test_directed_graph by passing that string to the tester constructor.
 !*/
 public:
 graph_tester (
 ) :
 tester ("test_graph",
 "Runs tests on the graph component.")
 {}
 void perform_test (
 )
 {
 dlog << LINFO << "testing kernel_1a_c";
 graph_test<graph<int>::kernel_1a_c>();
 dlog << LINFO << "testing kernel_1a";
 graph_test<graph<int>::kernel_1a>();
 test_copy();
 }
 } a;
}