source: NonGTP/Boost/boost/graph/astar_search.hpp @ 857

Revision 857, 13.2 KB checked in by igarcia, 19 years ago (diff)
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[857]1
2
3//
4//=======================================================================
5// Copyright (c) 2004 Kristopher Beevers
6//
7// Distributed under the Boost Software License, Version 1.0. (See
8// accompanying file LICENSE_1_0.txt or copy at
9// http://www.boost.org/LICENSE_1_0.txt)
10//=======================================================================
11//
12
13#ifndef BOOST_GRAPH_ASTAR_SEARCH_HPP
14#define BOOST_GRAPH_ASTAR_SEARCH_HPP
15
16
17#include <functional>
18#include <boost/limits.hpp>
19#include <boost/graph/named_function_params.hpp>
20#include <boost/pending/mutable_queue.hpp>
21#include <boost/graph/relax.hpp>
22#include <boost/pending/indirect_cmp.hpp>
23#include <boost/graph/exception.hpp>
24#include <boost/graph/breadth_first_search.hpp>
25
26
27namespace boost {
28
29 
30  template <class Heuristic, class Graph>
31  struct AStarHeuristicConcept {
32    void constraints()
33    {
34      function_requires< CopyConstructibleConcept<Heuristic> >();
35      h(u);
36    }
37    Heuristic h;
38    typename graph_traits<Graph>::vertex_descriptor u;
39  };
40 
41 
42  template <class Graph, class CostType>
43  class astar_heuristic : public std::unary_function<
44    typename graph_traits<Graph>::vertex_descriptor, CostType>
45  {
46  public:
47    typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
48    astar_heuristic() {}
49    CostType operator()(Vertex u) { return static_cast<CostType>(0); }
50  };
51 
52
53 
54  template <class Visitor, class Graph>
55  struct AStarVisitorConcept {
56    void constraints()
57    {
58      function_requires< CopyConstructibleConcept<Visitor> >();
59      vis.initialize_vertex(u, g);
60      vis.discover_vertex(u, g);
61      vis.examine_vertex(u, g);
62      vis.examine_edge(e, g);
63      vis.edge_relaxed(e, g);
64      vis.edge_not_relaxed(e, g);
65      vis.black_target(e, g);
66      vis.finish_vertex(u, g);
67    }
68    Visitor vis;
69    Graph g;
70    typename graph_traits<Graph>::vertex_descriptor u;
71    typename graph_traits<Graph>::edge_descriptor e;
72  };
73 
74 
75  template <class Visitors = null_visitor>
76  class astar_visitor : public bfs_visitor<Visitors> {
77  public:
78    astar_visitor() {}
79    astar_visitor(Visitors vis)
80      : bfs_visitor<Visitors>(vis) {}
81 
82    template <class Edge, class Graph>
83    void edge_relaxed(Edge e, Graph& g) {
84      invoke_visitors(this->m_vis, e, g, on_edge_relaxed());
85    }
86    template <class Edge, class Graph>
87    void edge_not_relaxed(Edge e, Graph& g) {
88      invoke_visitors(this->m_vis, e, g, on_edge_not_relaxed());     
89    }
90  private:
91    template <class Edge, class Graph>
92    void tree_edge(Edge e, Graph& g) {}
93    template <class Edge, class Graph>
94    void non_tree_edge(Edge e, Graph& g) {}
95  };
96  template <class Visitors>
97  astar_visitor<Visitors>
98  make_astar_visitor(Visitors vis) {
99    return astar_visitor<Visitors>(vis);
100  }
101  typedef astar_visitor<> default_astar_visitor;
102 
103
104  namespace detail {
105   
106    template <class AStarHeuristic, class UniformCostVisitor,
107              class UpdatableQueue, class PredecessorMap,
108              class CostMap, class DistanceMap, class WeightMap,
109              class ColorMap, class BinaryFunction,
110              class BinaryPredicate>
111    struct astar_bfs_visitor
112    {
113     
114      typedef typename property_traits<CostMap>::value_type C;
115      typedef typename property_traits<ColorMap>::value_type ColorValue;
116      typedef color_traits<ColorValue> Color;
117     
118     
119      astar_bfs_visitor(AStarHeuristic h, UniformCostVisitor vis,
120                        UpdatableQueue& Q, PredecessorMap p,
121                        CostMap c, DistanceMap d, WeightMap w,
122                        ColorMap col, BinaryFunction combine,
123                        BinaryPredicate compare, C zero)
124        : m_h(h), m_vis(vis), m_Q(Q), m_predecessor(p), m_cost(c),
125          m_distance(d), m_weight(w), m_color(col),
126          m_combine(combine), m_compare(compare), m_zero(zero) {}
127     
128     
129      template <class Vertex, class Graph>
130      void initialize_vertex(Vertex u, Graph& g) {
131        m_vis.initialize_vertex(u, g);
132      }
133      template <class Vertex, class Graph>
134      void discover_vertex(Vertex u, Graph& g) {
135        m_vis.discover_vertex(u, g);
136      }
137      template <class Vertex, class Graph>
138      void examine_vertex(Vertex u, Graph& g) {
139        m_vis.examine_vertex(u, g);
140      }
141      template <class Vertex, class Graph>
142      void finish_vertex(Vertex u, Graph& g) {
143        m_vis.finish_vertex(u, g);
144      }
145      template <class Edge, class Graph>
146      void examine_edge(Edge e, Graph& g) {
147        if (m_compare(get(m_weight, e), m_zero))
148          throw negative_edge();
149        m_vis.examine_edge(e, g);
150      }
151      template <class Edge, class Graph>
152      void non_tree_edge(Edge, Graph&) {}
153     
154     
155     
156      template <class Edge, class Graph>
157      void tree_edge(Edge e, Graph& g) {
158        m_decreased = relax(e, g, m_weight, m_predecessor, m_distance,
159                            m_combine, m_compare);
160        if(m_decreased) {
161          m_vis.edge_relaxed(e, g);
162          put(m_cost, target(e, g),
163              m_combine(get(m_distance, target(e, g)),
164                        m_h(target(e, g))));
165        } else
166          m_vis.edge_not_relaxed(e, g);
167      }
168     
169     
170      template <class Edge, class Graph>
171      void gray_target(Edge e, Graph& g) {
172        m_decreased = relax(e, g, m_weight, m_predecessor, m_distance,
173                            m_combine, m_compare);
174        if(m_decreased) {
175          put(m_cost, target(e, g),
176              m_combine(get(m_distance, target(e, g)),
177                        m_h(target(e, g))));
178          m_Q.update(target(e, g));
179          m_vis.edge_relaxed(e, g);
180        } else
181          m_vis.edge_not_relaxed(e, g);
182      }
183     
184     
185      template <class Edge, class Graph>
186      void black_target(Edge e, Graph& g) {
187        m_decreased = relax(e, g, m_weight, m_predecessor, m_distance,
188                            m_combine, m_compare);
189        if(m_decreased) {
190          m_vis.edge_relaxed(e, g);
191          put(m_cost, target(e, g),
192              m_combine(get(m_distance, target(e, g)),
193                        m_h(target(e, g))));
194          m_Q.push(target(e, g));
195          put(m_color, target(e, g), Color::gray());
196          m_vis.black_target(e, g);
197        } else
198          m_vis.edge_not_relaxed(e, g);
199      }
200     
201     
202     
203      AStarHeuristic m_h;
204      UniformCostVisitor m_vis;
205      UpdatableQueue& m_Q;
206      PredecessorMap m_predecessor;
207      CostMap m_cost;
208      DistanceMap m_distance;
209      WeightMap m_weight;
210      ColorMap m_color;
211      BinaryFunction m_combine;
212      BinaryPredicate m_compare;
213      bool m_decreased;
214      C m_zero;
215     
216    };
217   
218  } // namespace detail
219
220 
221 
222  template <typename VertexListGraph, typename AStarHeuristic,
223            typename AStarVisitor, typename PredecessorMap,
224            typename CostMap, typename DistanceMap,
225            typename WeightMap, typename ColorMap,
226            typename VertexIndexMap,
227            typename CompareFunction, typename CombineFunction,
228            typename CostInf, typename CostZero>
229  inline void
230  astar_search_no_init
231    (VertexListGraph &g,
232     typename graph_traits<VertexListGraph>::vertex_descriptor s,
233     AStarHeuristic h, AStarVisitor vis,
234     PredecessorMap predecessor, CostMap cost,
235     DistanceMap distance, WeightMap weight,
236     ColorMap color, VertexIndexMap index_map,
237     CompareFunction compare, CombineFunction combine,
238     CostInf inf, CostZero zero)
239  {
240    typedef indirect_cmp<CostMap, CompareFunction> IndirectCmp;
241    IndirectCmp icmp(cost, compare);
242 
243    typedef typename graph_traits<VertexListGraph>::vertex_descriptor
244      Vertex;
245    typedef mutable_queue<Vertex, std::vector<Vertex>,
246        IndirectCmp, VertexIndexMap>
247      MutableQueue;
248    MutableQueue Q(num_vertices(g), icmp, index_map);
249 
250    detail::astar_bfs_visitor<AStarHeuristic, AStarVisitor,
251        MutableQueue, PredecessorMap, CostMap, DistanceMap,
252        WeightMap, ColorMap, CombineFunction, CompareFunction>
253      bfs_vis(h, vis, Q, predecessor, cost, distance, weight,
254              color, combine, compare, zero);
255 
256    breadth_first_visit(g, s, Q, bfs_vis, color);
257  }
258 
259 
260  // Non-named parameter interface
261  template <typename VertexListGraph, typename AStarHeuristic,
262            typename AStarVisitor, typename PredecessorMap,
263            typename CostMap, typename DistanceMap,
264            typename WeightMap, typename VertexIndexMap,
265            typename ColorMap,
266            typename CompareFunction, typename CombineFunction,
267            typename CostInf, typename CostZero>
268  inline void
269  astar_search
270    (VertexListGraph &g,
271     typename graph_traits<VertexListGraph>::vertex_descriptor s,
272     AStarHeuristic h, AStarVisitor vis,
273     PredecessorMap predecessor, CostMap cost,
274     DistanceMap distance, WeightMap weight,
275     VertexIndexMap index_map, ColorMap color,
276     CompareFunction compare, CombineFunction combine,
277     CostInf inf, CostZero zero)
278  {
279   
280    typedef typename property_traits<ColorMap>::value_type ColorValue;
281    typedef color_traits<ColorValue> Color;
282    typename graph_traits<VertexListGraph>::vertex_iterator ui, ui_end;
283    for (tie(ui, ui_end) = vertices(g); ui != ui_end; ++ui) {
284      put(color, *ui, Color::white());
285      put(distance, *ui, inf);
286      put(cost, *ui, inf);
287      put(predecessor, *ui, *ui);
288    }
289    put(distance, s, zero);
290    put(cost, s, h(s));
291   
292    astar_search_no_init
293      (g, s, h, vis, predecessor, cost, distance, weight,
294       color, index_map, compare, combine, inf, zero);
295   
296  }
297 
298 
299 
300  namespace detail {
301    template <class VertexListGraph, class AStarHeuristic,
302              class CostMap, class DistanceMap, class WeightMap,
303              class IndexMap, class ColorMap, class Params>
304    inline void
305    astar_dispatch2
306      (VertexListGraph& g,
307       typename graph_traits<VertexListGraph>::vertex_descriptor s,
308       AStarHeuristic h, CostMap cost, DistanceMap distance,
309       WeightMap weight, IndexMap index_map, ColorMap color,
310       const Params& params)
311    {
312      dummy_property_map p_map;
313      typedef typename property_traits<CostMap>::value_type C;
314      astar_search
315        (g, s, h,
316         choose_param(get_param(params, graph_visitor),
317                      make_astar_visitor(null_visitor())),
318         choose_param(get_param(params, vertex_predecessor), p_map),
319         cost, distance, weight, index_map, color,
320         choose_param(get_param(params, distance_compare_t()),
321                      std::less<C>()),
322         choose_param(get_param(params, distance_combine_t()),
323                      closed_plus<C>()),
324         choose_param(get_param(params, distance_inf_t()),
325                      std::numeric_limits<C>::max BOOST_PREVENT_MACRO_SUBSTITUTION ()),
326         choose_param(get_param(params, distance_zero_t()),
327                      C()));
328    }
329 
330    template <class VertexListGraph, class AStarHeuristic,
331              class CostMap, class DistanceMap, class WeightMap,
332              class IndexMap, class ColorMap, class Params>
333    inline void
334    astar_dispatch1
335      (VertexListGraph& g,
336       typename graph_traits<VertexListGraph>::vertex_descriptor s,
337       AStarHeuristic h, CostMap cost, DistanceMap distance,
338       WeightMap weight, IndexMap index_map, ColorMap color,
339       const Params& params)
340    {
341      typedef typename property_traits<WeightMap>::value_type D;
342      typename std::vector<D>::size_type
343        n = is_default_param(distance) ? num_vertices(g) : 1;
344      std::vector<D> distance_map(n);
345      n = is_default_param(cost) ? num_vertices(g) : 1;
346      std::vector<D> cost_map(n);
347      std::vector<default_color_type> color_map(num_vertices(g));
348      default_color_type c = white_color;
349 
350      detail::astar_dispatch2
351        (g, s, h,
352         choose_param(cost, make_iterator_property_map
353                      (cost_map.begin(), index_map,
354                       cost_map[0])),
355         choose_param(distance, make_iterator_property_map
356                      (distance_map.begin(), index_map,
357                       distance_map[0])),
358         weight, index_map,
359         choose_param(color, make_iterator_property_map
360                      (color_map.begin(), index_map, c)),
361         params);
362    }
363  } // namespace detail
364 
365 
366  // Named parameter interface
367  template <typename VertexListGraph,
368            typename AStarHeuristic,
369            typename P, typename T, typename R>
370  void
371  astar_search
372    (VertexListGraph &g,
373     typename graph_traits<VertexListGraph>::vertex_descriptor s,
374     AStarHeuristic h, const bgl_named_params<P, T, R>& params)
375  {
376   
377    detail::astar_dispatch1
378      (g, s, h,
379       get_param(params, vertex_rank),
380       get_param(params, vertex_distance),
381       choose_const_pmap(get_param(params, edge_weight), g, edge_weight),
382       choose_const_pmap(get_param(params, vertex_index), g, vertex_index),
383       get_param(params, vertex_color),
384       params);
385   
386  }
387 
388} // namespace boost
389
390#endif // BOOST_GRAPH_ASTAR_SEARCH_HPP
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