Skip to content

vf2_sub_graph_iso.hpp: fix bug when subgraph is filtered #282

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
count0 wants to merge 3 commits into
base: develop
Choose a base branch
from
Open

vf2_sub_graph_iso.hpp: fix bug when subgraph is filtered #282

Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
35a4607
vf2_sub_graph_iso.hpp: fix bug when subgraph is filtered
count0 Jan 2, 2022
3354d3d
vf2_sub_graph_iso.hpp: change get_num_vertices() to O(1) for unfilter…
count0 Jan 4, 2022
1405d94
Change identifier style
jeremy-murphy Sep 13, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
33 changes: 27 additions & 6 deletions include/boost/graph/vf2_sub_graph_iso.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -75,6 +75,14 @@ template < typename Graph1, typename Graph2 > struct vf2_print_callback

namespace detail
{
template <typename Graph>
typename graph_traits<Graph>::vertices_size_type get_num_vertices(Graph& g)
{
typename graph_traits<Graph>::vertices_size_type N = 0;
BGL_FORALL_VERTICES_T(v, g, Graph)
N++;
return N;
Copy link
Copy Markdown
Contributor

@jakobandersen jakobandersen Jan 4, 2022

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
typename graph_traits<Graph>::vertices_size_type N = 0;
BGL_FORALL_VERTICES_T(v, g, Graph)
N++;
return N;
typedef typename graph_traits<Graph>::vertex_iterator iter;
std::pair<iter, iter> vs = vertices(g);
return std::distance(vs.first, vs.second);

The old num_vertices() takes constant time, so having a raw loop which forces linear time is not ok. With std::distance() it should only take linear time when needed (e.g., for filtered_graph).

Copy link
Copy Markdown
Author

@count0 count0 Jan 4, 2022

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is a good suggestion!

}

// State associated with a single graph (graph_this)
template < typename GraphThis, typename GraphOther, typename IndexMapThis,
Expand Down Expand Up @@ -446,6 +454,8 @@ namespace detail
base_state< Graph1, Graph2, IndexMap1, IndexMap2 > state1_;
base_state< Graph2, Graph1, IndexMap2, IndexMap1 > state2_;

graph1_size_type NV1_;

// Three helper functions used in Feasibility and Valid functions to
// test terminal set counts when testing for:
// - graph sub-graph monomorphism, or
Expand Down Expand Up @@ -484,6 +494,7 @@ namespace detail
, vertex_comp_(vertex_comp)
, state1_(graph1, graph2, index_map1, index_map2)
, state2_(graph2, graph1, index_map2, index_map1)
, NV1_(get_num_vertices(graph1))
{
}

Expand Down Expand Up @@ -702,7 +713,7 @@ namespace detail
// Returns true if a mapping was found
bool success() const
{
return state1_.count() == num_vertices(graph1_);
return state1_.count() == NV1_;
}

// Returns true if a state is valid
Expand Down Expand Up @@ -754,7 +765,7 @@ namespace detail
typename IndexMap2, typename VertexOrder1,
typename EdgeEquivalencePredicate, typename VertexEquivalencePredicate,
typename SubGraphIsoMapCallback, problem_selector problem_selection >
bool match(const Graph1& graph1, const Graph2& graph2,
bool match(const Graph1&, const Graph2& graph2,
SubGraphIsoMapCallback user_callback, const VertexOrder1& vertex_order1,
state< Graph1, Graph2, IndexMap1, IndexMap2, EdgeEquivalencePredicate,
VertexEquivalencePredicate, SubGraphIsoMapCallback,
Expand Down Expand Up @@ -976,14 +987,19 @@ namespace detail
(BinaryPredicateConcept< VertexEquivalencePredicate,
vertex_small_type, vertex_large_type >));

typename graph_traits< GraphSmall >::vertices_size_type num_vertices_small
= get_num_vertices(graph_small);
typename graph_traits< GraphLarge >::vertices_size_type num_vertices_large
= get_num_vertices(graph_large);

// Vertex order requirements
BOOST_CONCEPT_ASSERT((ContainerConcept< VertexOrderSmall >));
typedef typename VertexOrderSmall::value_type order_value_type;
BOOST_STATIC_ASSERT(
(is_same< vertex_small_type, order_value_type >::value));
BOOST_ASSERT(num_vertices(graph_small) == vertex_order_small.size());
BOOST_ASSERT(num_vertices_small == vertex_order_small.size());

if (num_vertices(graph_small) > num_vertices(graph_large))
if (num_vertices_small > num_vertices_large)
return false;

typename graph_traits< GraphSmall >::edges_size_type num_edges_small
Expand Down Expand Up @@ -1182,13 +1198,18 @@ bool vf2_graph_iso(const Graph1& graph1, const Graph2& graph2,
BOOST_CONCEPT_ASSERT((BinaryPredicateConcept< VertexEquivalencePredicate,
vertex1_type, vertex2_type >));

typename graph_traits< Graph1 >::vertices_size_type num_vertices1
= detail::get_num_vertices(graph1);
typename graph_traits< Graph2 >::vertices_size_type num_vertices2
= detail::get_num_vertices(graph2);

// Vertex order requirements
BOOST_CONCEPT_ASSERT((ContainerConcept< VertexOrder1 >));
typedef typename VertexOrder1::value_type order_value_type;
BOOST_STATIC_ASSERT((is_same< vertex1_type, order_value_type >::value));
BOOST_ASSERT(num_vertices(graph1) == vertex_order1.size());
BOOST_ASSERT(num_vertices1 == vertex_order1.size());

if (num_vertices(graph1) != num_vertices(graph2))
if (num_vertices1 != num_vertices2)
return false;

typename graph_traits< Graph1 >::edges_size_type num_edges1
Expand Down