comparison DEPENDENCIES/generic/include/boost/graph/is_kuratowski_subgraph.hpp @ 16:2665513ce2d3

Add boost headers

+//=======================================================================
+// Copyright 2007 Aaron Windsor
+//
+// 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)
+//=======================================================================
+#ifndef __IS_KURATOWSKI_SUBGRAPH_HPP__
+#define __IS_KURATOWSKI_SUBGRAPH_HPP__
+
+#include <boost/config.hpp>
+#include <boost/tuple/tuple.hpp>   //for tie
+#include <boost/property_map/property_map.hpp>
+#include <boost/graph/properties.hpp>
+#include <boost/graph/isomorphism.hpp>
+#include <boost/graph/adjacency_list.hpp>
+
+#include <algorithm>
+#include <vector>
+#include <set>
+
+
+
+namespace boost
+{
+  
+  namespace detail
+  {
+
+    template <typename Graph>
+    Graph make_K_5()
+    {
+      typename graph_traits<Graph>::vertex_iterator vi, vi_end, inner_vi;
+      Graph K_5(5);
+      for(boost::tie(vi,vi_end) = vertices(K_5); vi != vi_end; ++vi)
+        for(inner_vi = next(vi); inner_vi != vi_end; ++inner_vi)
+          add_edge(*vi, *inner_vi, K_5);
+      return K_5;
+    }
+
+
+    template <typename Graph>
+    Graph make_K_3_3()
+    {
+      typename graph_traits<Graph>::vertex_iterator 
+        vi, vi_end, bipartition_start, inner_vi;
+      Graph K_3_3(6);
+      bipartition_start = next(next(next(vertices(K_3_3).first)));
+      for(boost::tie(vi, vi_end) = vertices(K_3_3); vi != bipartition_start; ++vi)
+        for(inner_vi= bipartition_start; inner_vi != vi_end; ++inner_vi)
+          add_edge(*vi, *inner_vi, K_3_3);
+      return K_3_3;
+    }
+
+
+    template <typename AdjacencyList, typename Vertex>
+    void contract_edge(AdjacencyList& neighbors, Vertex u, Vertex v)
+    {
+      // Remove u from v's neighbor list
+      neighbors[v].erase(std::remove(neighbors[v].begin(), 
+                                     neighbors[v].end(), u
+                                     ), 
+                         neighbors[v].end()
+                         );
+      
+      // Replace any references to u with references to v
+      typedef typename AdjacencyList::value_type::iterator 
+        adjacency_iterator_t;
+      
+      adjacency_iterator_t u_neighbor_end = neighbors[u].end();
+      for(adjacency_iterator_t u_neighbor_itr = neighbors[u].begin();
+          u_neighbor_itr != u_neighbor_end; ++u_neighbor_itr
+          )
+        {
+          Vertex u_neighbor(*u_neighbor_itr);
+          std::replace(neighbors[u_neighbor].begin(), 
+                       neighbors[u_neighbor].end(), u, v
+                       );
+        }
+      
+      // Remove v from u's neighbor list
+      neighbors[u].erase(std::remove(neighbors[u].begin(), 
+                                     neighbors[u].end(), v
+                                     ), 
+                         neighbors[u].end()
+                         );
+      
+      // Add everything in u's neighbor list to v's neighbor list
+      std::copy(neighbors[u].begin(), 
+                neighbors[u].end(), 
+                std::back_inserter(neighbors[v])
+                );
+      
+      // Clear u's neighbor list
+      neighbors[u].clear();
+
+    }
+
+    enum target_graph_t { tg_k_3_3, tg_k_5};
+
+  } // namespace detail
+
+
+
+
+  template <typename Graph, typename ForwardIterator, typename VertexIndexMap>
+  bool is_kuratowski_subgraph(const Graph& g,
+                              ForwardIterator begin, 
+                              ForwardIterator end, 
+                              VertexIndexMap vm
+                              )
+  {
+
+    typedef typename graph_traits<Graph>::vertex_descriptor vertex_t;
+    typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator_t;
+    typedef typename graph_traits<Graph>::edge_descriptor edge_t;
+    typedef typename graph_traits<Graph>::edges_size_type e_size_t;
+    typedef typename graph_traits<Graph>::vertices_size_type v_size_t;
+    typedef typename std::vector<vertex_t> v_list_t;
+    typedef typename v_list_t::iterator v_list_iterator_t;
+    typedef iterator_property_map
+      <typename std::vector<v_list_t>::iterator, VertexIndexMap> 
+      vertex_to_v_list_map_t;
+
+    typedef adjacency_list<vecS, vecS, undirectedS> small_graph_t;
+
+    detail::target_graph_t target_graph = detail::tg_k_3_3; //unless we decide otherwise later
+
+    static small_graph_t K_5(detail::make_K_5<small_graph_t>());
+
+    static small_graph_t K_3_3(detail::make_K_3_3<small_graph_t>());
+
+    v_size_t n_vertices(num_vertices(g));
+    v_size_t max_num_edges(3*n_vertices - 5);
+
+    std::vector<v_list_t> neighbors_vector(n_vertices);
+    vertex_to_v_list_map_t neighbors(neighbors_vector.begin(), vm);
+
+    e_size_t count = 0;
+    for(ForwardIterator itr = begin; itr != end; ++itr)
+      {
+
+        if (count++ > max_num_edges)
+          return false;
+
+        edge_t e(*itr);
+        vertex_t u(source(e,g));
+        vertex_t v(target(e,g));
+
+        neighbors[u].push_back(v);
+        neighbors[v].push_back(u);
+
+      }
+
+
+    for(v_size_t max_size = 2; max_size < 5; ++max_size)
+      {
+
+        vertex_iterator_t vi, vi_end;
+        for(boost::tie(vi,vi_end) = vertices(g); vi != vi_end; ++vi)
+          {
+            vertex_t v(*vi);
+
+            //a hack to make sure we don't contract the middle edge of a path
+            //of four degree-3 vertices
+            if (max_size == 4 && neighbors[v].size() == 3)
+              {
+                if (neighbors[neighbors[v][0]].size() +
+                    neighbors[neighbors[v][1]].size() +
+                    neighbors[neighbors[v][2]].size()
+                    < 11 // so, it has two degree-3 neighbors
+                    )
+                  continue;
+              }
+
+            while (neighbors[v].size() > 0 && neighbors[v].size() < max_size)
+              {
+                // Find one of v's neighbors u such that v and u
+                // have no neighbors in common. We'll look for such a 
+                // neighbor with a naive cubic-time algorithm since the 
+                // max size of any of the neighbor sets we'll consider 
+                // merging is 3
+                
+                bool neighbor_sets_intersect = false;
+                
+                vertex_t min_u = graph_traits<Graph>::null_vertex();
+                vertex_t u;
+                v_list_iterator_t v_neighbor_end = neighbors[v].end();
+                for(v_list_iterator_t v_neighbor_itr = neighbors[v].begin();
+                    v_neighbor_itr != v_neighbor_end; 
+                    ++v_neighbor_itr
+                    )
+                  {
+                    neighbor_sets_intersect = false;
+                    u = *v_neighbor_itr;
+                    v_list_iterator_t u_neighbor_end = neighbors[u].end();
+                    for(v_list_iterator_t u_neighbor_itr = 
+                          neighbors[u].begin();
+                        u_neighbor_itr != u_neighbor_end && 
+                          !neighbor_sets_intersect; 
+                        ++u_neighbor_itr
+                        )
+                      {
+                        for(v_list_iterator_t inner_v_neighbor_itr = 
+                              neighbors[v].begin();
+                            inner_v_neighbor_itr != v_neighbor_end; 
+                            ++inner_v_neighbor_itr
+                            )
+                          {
+                            if (*u_neighbor_itr == *inner_v_neighbor_itr)
+                              {
+                                neighbor_sets_intersect = true;
+                                break;
+                              }
+                          }
+                        
+                      }
+                    if (!neighbor_sets_intersect &&
+                        (min_u == graph_traits<Graph>::null_vertex() || 
+                         neighbors[u].size() < neighbors[min_u].size())
+                        )
+                      {
+                        min_u = u;
+                      }
+                        
+                  }
+
+                if (min_u == graph_traits<Graph>::null_vertex())
+                  // Exited the loop without finding an appropriate neighbor of
+                  // v, so v must be a lost cause. Move on to other vertices.
+                  break;
+                else
+                  u = min_u;
+
+                detail::contract_edge(neighbors, u, v);
+
+              }//end iteration over v's neighbors
+
+          }//end iteration through vertices v
+
+        if (max_size == 3)
+          {
+            // check to see whether we should go on to find a K_5
+            for(boost::tie(vi,vi_end) = vertices(g); vi != vi_end; ++vi)
+              if (neighbors[*vi].size() == 4)
+                {
+                  target_graph = detail::tg_k_5;
+                  break;
+                }
+
+            if (target_graph == detail::tg_k_3_3)
+              break;
+          }
+        
+      }//end iteration through max degree 2,3, and 4
+
+    
+    //Now, there should only be 5 or 6 vertices with any neighbors. Find them.
+    
+    v_list_t main_vertices;
+    vertex_iterator_t vi, vi_end;
+    
+    for(boost::tie(vi,vi_end) = vertices(g); vi != vi_end; ++vi)
+      {
+        if (!neighbors[*vi].empty())
+          main_vertices.push_back(*vi);
+      }
+    
+    // create a graph isomorphic to the contracted graph to test 
+    // against K_5 and K_3_3
+    small_graph_t contracted_graph(main_vertices.size());
+    std::map<vertex_t,typename graph_traits<small_graph_t>::vertex_descriptor> 
+      contracted_vertex_map;
+    
+    typename v_list_t::iterator itr, itr_end;
+    itr_end = main_vertices.end();
+    typename graph_traits<small_graph_t>::vertex_iterator 
+      si = vertices(contracted_graph).first;
+    
+    for(itr = main_vertices.begin(); itr != itr_end; ++itr, ++si)
+      {
+        contracted_vertex_map[*itr] = *si;
+      }
+
+    typename v_list_t::iterator jtr, jtr_end;
+    for(itr = main_vertices.begin(); itr != itr_end; ++itr)
+      {
+        jtr_end = neighbors[*itr].end();
+        for(jtr = neighbors[*itr].begin(); jtr != jtr_end; ++jtr)
+          {
+            if (get(vm,*itr) < get(vm,*jtr))
+              {
+                add_edge(contracted_vertex_map[*itr],
+                         contracted_vertex_map[*jtr],
+                         contracted_graph
+                         );
+              }
+          }
+      }
+    
+    if (target_graph == detail::tg_k_5)
+      {
+        return boost::isomorphism(K_5,contracted_graph);
+      }
+    else //target_graph == tg_k_3_3
+      {
+        return boost::isomorphism(K_3_3,contracted_graph);
+      }
+    
+    
+  }
+
+
+
+
+
+  template <typename Graph, typename ForwardIterator>
+  bool is_kuratowski_subgraph(const Graph& g, 
+                              ForwardIterator begin, 
+                              ForwardIterator end
+                              )
+  {
+    return is_kuratowski_subgraph(g, begin, end, get(vertex_index,g));
+  }
+
+
+
+  
+}
+
+#endif //__IS_KURATOWSKI_SUBGRAPH_HPP__