1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/*PGR-GNU*****************************************************************
File: depthFirstSearch.hpp
Copyright (c) 2007-2026 pgRouting developers
Mail: project@pgrouting.org
Copyright (c) 2020 Ashish Kumar
Mail: ashishkr23438@gmail.com
------
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
********************************************************************PGR-GNU*/
#ifndef INCLUDE_TRAVERSAL_DEPTHFIRSTSEARCH_HPP_
#define INCLUDE_TRAVERSAL_DEPTHFIRSTSEARCH_HPP_
#pragma once
#include <vector>
#include <map>
#include <cstdint>
#include <visitors/dfs_visitor.hpp>
#include <boost/graph/depth_first_search.hpp>
#include <boost/graph/undirected_dfs.hpp>
#include "cpp_common/base_graph.hpp"
#include "cpp_common/interruption.hpp"
#include "c_types/mst_rt.h"
namespace pgrouting {
namespace functions {
//*************************************************************
template < class G >
class Pgr_depthFirstSearch {
public:
typedef typename G::V V;
typedef typename G::E E;
/** @name DepthFirstSearch
* @{
*
*/
/** @brief depthFirstSearch function
*
* It does all the processing and returns the results.
*
* @param graph the graph containing the edges
* @param roots the root vertices
* @param max_depth the maximum depth of traversal
* @param directed whether the graph is directed or undirected
*
* @returns results, when results are found
*
* @see [boost::depth_first_search]
* (https://www.boost.org/libs/graph/doc/depth_first_search.html)
* @see [boost::undirected_dfs]
* (https://www.boost.org/libs/graph/doc/undirected_dfs.html)
*/
std::vector < MST_rt > depthFirstSearch(
G &graph,
std::vector < int64_t > roots,
bool directed,
int64_t max_depth) {
std::vector < MST_rt > results;
for (auto root : roots) {
results.push_back({root, 0, root, root, -1, 0.0, 0.0});
if (graph.has_vertex(root)) {
std::vector<E> visited_order;
auto v_root(graph.get_V(root));
depthFirstSearch_single_vertex(graph, v_root, visited_order, directed, max_depth);
auto result = get_results(visited_order, root, max_depth, graph);
results.insert(results.end(), result.begin(), result.end());
}
}
return results;
}
//@}
private:
/** @brief Calls the Boost function
*
* Calls [boost::depth_first_search]
* (https://www.boost.org/libs/graph/doc/depth_first_search.html)
* and [boost::undirected_dfs]
* (https://www.boost.org/libs/graph/doc/undirected_dfs.html)
* for directed graphs and undirected graphs, respectively.
*
* @param graph the graph containing the edges
* @param root the root vertex
* @param visited_order vector which will contain the edges of the resulting traversal
* @param directed whether the graph is directed or undirected
* @param max_depth Upper limit for depth to be returned
*
* @returns bool @b true, when results are found
*/
bool depthFirstSearch_single_vertex(
G &graph,
V root,
std::vector < E > &visited_order,
bool directed,
int64_t max_depth) {
using dfs_visitor = visitors::Dfs_visitor < V, E, G >;
// Exterior property storage containers
std::vector < boost::default_color_type > colors(boost::num_vertices(graph.graph));
std::map < E, boost::default_color_type > edge_color;
auto i_map = boost::get(boost::vertex_index, graph.graph);
// Iterator property maps which record the color of each vertex and edge, respectively
auto vertex_color_map = boost::make_iterator_property_map(colors.begin(), i_map);
auto edge_color_map = boost::make_assoc_property_map(edge_color);
auto vis = dfs_visitor(root, visited_order, max_depth, colors, graph);
/* abort in case of an interruption occurs (e.g. the query is being cancelled) */
CHECK_FOR_INTERRUPTS();
try {
if (directed) {
boost::depth_first_search(graph.graph, vis, vertex_color_map, root);
} else {
boost::undirected_dfs(graph.graph, vis, vertex_color_map, edge_color_map, root);
}
} catch(found_goals &) {
{}
} catch (boost::exception const& ex) {
(void)ex;
throw;
} catch (std::exception &e) {
(void)e;
throw;
} catch (...) {
throw;
}
return true;
}
/** @brief to get the results
*
* Uses the `visited_order` of vertices to get the results.
* Selects only those nodes in the final result whose
* depth is less than the `max_depth`.
*
* @param visited_order vector which contains the edges of the resulting traversal
* @param root the root vertex
* @param max_depth the maximum depth of traversal
* @param graph the graph containing the edges
*
* @returns `results` vector
*/
template < typename T >
std::vector < MST_rt > get_results(
T visited_order,
int64_t root,
int64_t max_depth,
const G &graph) {
std::vector < MST_rt > results;
std::vector < double > agg_cost(graph.num_vertices(), 0);
std::vector < int64_t > depth(graph.num_vertices(), 0);
for (const auto edge : visited_order) {
auto u = graph.source(edge);
auto v = graph.target(edge);
agg_cost[v] = agg_cost[u] + graph[edge].cost;
depth[v] = depth[u] + 1;
if (max_depth >= depth[v]) {
results.push_back({
root,
depth[v],
graph[u].id,
graph[v].id,
graph[edge].id,
graph[edge].cost,
agg_cost[v]
});
}
}
return results;
}
};
} // namespace functions
} // namespace pgrouting
#endif // INCLUDE_TRAVERSAL_DEPTHFIRSTSEARCH_HPP_
|
