Added boost header

test/external/boost/graph/kruskal_min_spanning_tree.hpp

@@ -0,0 +1,155 @@
+//
+//=======================================================================
+// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
+// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
+//
+// 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 BOOST_GRAPH_MST_KRUSKAL_HPP
+#define BOOST_GRAPH_MST_KRUSKAL_HPP
+
+/*
+ *Minimum Spanning Tree 
+ *         Kruskal Algorithm
+ *
+ *Requirement:
+ *      undirected graph
+ */
+
+#include <vector>
+#include <queue>
+#include <functional>
+
+#include <boost/property_map/property_map.hpp>
+#include <boost/graph/graph_concepts.hpp>
+#include <boost/graph/named_function_params.hpp>
+#include <boost/pending/disjoint_sets.hpp>
+#include <boost/pending/indirect_cmp.hpp>
+
+
+namespace boost {
+
+  // Kruskal's algorithm for Minimum Spanning Tree
+  //
+  // This is a greedy algorithm to calculate the Minimum Spanning Tree
+  // for an undirected graph with weighted edges. The output will be a
+  // set of edges.
+  //
+
+  namespace detail {
+
+    template <class Graph, class OutputIterator, 
+              class Rank, class Parent, class Weight>
+    void
+    kruskal_mst_impl(const Graph& G, 
+                     OutputIterator spanning_tree_edges, 
+                     Rank rank, Parent parent, Weight weight)
+    {
+      if (num_vertices(G) == 0) return; // Nothing to do in this case
+      typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
+      typedef typename graph_traits<Graph>::edge_descriptor Edge;
+      function_requires<VertexListGraphConcept<Graph> >();
+      function_requires<EdgeListGraphConcept<Graph> >();
+      function_requires<OutputIteratorConcept<OutputIterator, Edge> >();
+      function_requires<ReadWritePropertyMapConcept<Rank, Vertex> >();
+      function_requires<ReadWritePropertyMapConcept<Parent, Vertex> >();
+      function_requires<ReadablePropertyMapConcept<Weight, Edge> >();
+      typedef typename property_traits<Weight>::value_type W_value;
+      typedef typename property_traits<Rank>::value_type R_value;
+      typedef typename property_traits<Parent>::value_type P_value;
+      function_requires<ComparableConcept<W_value> >();
+      function_requires<ConvertibleConcept<P_value, Vertex> >();
+      function_requires<IntegerConcept<R_value> >();
+
+      disjoint_sets<Rank, Parent>  dset(rank, parent);
+
+      typename graph_traits<Graph>::vertex_iterator ui, uiend;
+      for (boost::tie(ui, uiend) = vertices(G); ui != uiend; ++ui)
+        dset.make_set(*ui);
+
+      typedef indirect_cmp<Weight, std::greater<W_value> > weight_greater;
+      weight_greater wl(weight);
+      std::priority_queue<Edge, std::vector<Edge>, weight_greater> Q(wl);
+      /*push all edge into Q*/
+      typename graph_traits<Graph>::edge_iterator ei, eiend;
+      for (boost::tie(ei, eiend) = edges(G); ei != eiend; ++ei) 
+        Q.push(*ei);
+
+      while (! Q.empty()) {
+        Edge e = Q.top();
+        Q.pop();
+        Vertex u = dset.find_set(source(e, G));
+        Vertex v = dset.find_set(target(e, G));
+        if ( u != v ) {
+          *spanning_tree_edges++ = e;
+          dset.link(u, v);
+        }
+      }
+    }
+
+  } // namespace detail 
+
+  // Named Parameters Variants
+
+  template <class Graph, class OutputIterator>
+  inline void 
+  kruskal_minimum_spanning_tree(const Graph& g,
+                                OutputIterator spanning_tree_edges)
+  {
+    typedef typename graph_traits<Graph>::vertices_size_type size_type;
+    typedef typename graph_traits<Graph>::vertex_descriptor vertex_t;
+    typedef typename property_map<Graph, vertex_index_t>::type index_map_t;
+    if (num_vertices(g) == 0) return; // Nothing to do in this case
+    typename graph_traits<Graph>::vertices_size_type
+      n = num_vertices(g);
+    std::vector<size_type> rank_map(n);
+    std::vector<vertex_t> pred_map(n);
+
+    detail::kruskal_mst_impl
+      (g, spanning_tree_edges, 
+       make_iterator_property_map(rank_map.begin(), get(vertex_index, g), rank_map[0]),
+       make_iterator_property_map(pred_map.begin(), get(vertex_index, g), pred_map[0]),
+       get(edge_weight, g));
+  }
+
+  template <class Graph, class OutputIterator, class P, class T, class R>
+  inline void
+  kruskal_minimum_spanning_tree(const Graph& g,
+                                OutputIterator spanning_tree_edges, 
+                                const bgl_named_params<P, T, R>& params)
+  {
+    typedef typename graph_traits<Graph>::vertices_size_type size_type;
+    typedef typename graph_traits<Graph>::vertex_descriptor vertex_t;
+    if (num_vertices(g) == 0) return; // Nothing to do in this case
+    typename graph_traits<Graph>::vertices_size_type n;
+    n = is_default_param(get_param(params, vertex_rank))
+                                   ? num_vertices(g) : 1;
+    std::vector<size_type> rank_map(n);
+    n = is_default_param(get_param(params, vertex_predecessor))
+                                   ? num_vertices(g) : 1;
+    std::vector<vertex_t> pred_map(n);
+    
+    detail::kruskal_mst_impl
+      (g, spanning_tree_edges, 
+       choose_param
+       (get_param(params, vertex_rank), 
+        make_iterator_property_map
+        (rank_map.begin(), 
+         choose_pmap(get_param(params, vertex_index), g, vertex_index), rank_map[0])),
+       choose_param
+       (get_param(params, vertex_predecessor), 
+        make_iterator_property_map
+        (pred_map.begin(), 
+         choose_const_pmap(get_param(params, vertex_index), g, vertex_index), 
+         pred_map[0])),
+       choose_const_pmap(get_param(params, edge_weight), g, edge_weight));
+  }
+    
+} // namespace boost
+
+
+#endif // BOOST_GRAPH_MST_KRUSKAL_HPP
+