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
|
// ==========================================================================
// SeqAn - The Library for Sequence Analysis
// ==========================================================================
// Copyright (c) 2006-2026, Knut Reinert, FU Berlin
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of Knut Reinert or the FU Berlin nor the names of
// its contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL KNUT REINERT OR THE FU BERLIN BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
// DAMAGE.
//
// ==========================================================================
// Author: Tobias Raussch <rausch@embl.de>
// ==========================================================================
// Implementation of Breadth-First-Search.
// ==========================================================================
#ifndef INCLUDE_SEQAN_GRAPH_ALGORITHMS_BREADTH_FIRST_SEARCH_H_
#define INCLUDE_SEQAN_GRAPH_ALGORITHMS_BREADTH_FIRST_SEARCH_H_
namespace seqan2 {
// ============================================================================
// Forwards
// ============================================================================
// ============================================================================
// Tags, Classes, Enums
// ============================================================================
// ============================================================================
// Metafunctions
// ============================================================================
// ============================================================================
// Functions
// ============================================================================
// ----------------------------------------------------------------------------
// Function breadthFirstSearch()
// ----------------------------------------------------------------------------
/*!
* @fn breadthFirstSearch
* @headerfile <seqan/graph_algorithms.h>
* @brief Implements a breadth-first search on a graph.
*
* @signature void breadthFirstSearch(predecessor, distance, g, source);
*
* @param[out] predecessor A property map. The predecessor map stores implicitly the breadth-first tree.
* @param[out] distance A property map. The distance map indicates at what depth a vertex was discovered.
* @param[in] g Undirected Graph, Directed Graph
* @param[in] source A vertex descriptor. The breadth-first search is started from this vertex.
* Types: VertexDescriptor
*
* Breadth-first search computes the distance from source to all reachable vertices. It also produces a breath-first
* tree where each node has a predecessor/parent.
*
* @section Example
*
* @include demos/dox/graph_algorithms/breadth_first_search.cpp
*
* @include demos/dox/graph_algorithms/breadth_first_search.cpp.stdout
*
* @see depthFirstSearch
*/
template <typename TSpec, typename TVertexDescriptor, typename TPredecessorMap, typename TDistanceMap>
void breadthFirstSearch(TPredecessorMap & predecessor,
TDistanceMap & distance,
Graph<TSpec> const & g,
TVertexDescriptor const source)
{
typedef Graph<TSpec> TGraph;
typedef typename Iterator<TGraph, VertexIterator>::Type TVertexIterator;
typedef typename Value<TPredecessorMap>::Type TPredVal;
typedef typename Value<TDistanceMap>::Type TDistVal;
// Initialization
resizeVertexMap(predecessor, g);
resizeVertexMap(distance, g);
TPredVal nilPred = getNil<typename VertexDescriptor<TGraph>::Type>();
TDistVal infDist = _getInfinityDistance(distance);
String<bool> tokenMap;
resizeVertexMap(tokenMap, g);
TVertexIterator it(g);
for(;!atEnd(it);goNext(it)) {
assignProperty(tokenMap, getValue(it), false);
assignProperty(distance, getValue(it), infDist);
assignProperty(predecessor, getValue(it), nilPred);
}
assignProperty(tokenMap, source, true);
assignProperty(distance, source, 0);
assignProperty(predecessor, source, nilPred);
std::deque<TVertexDescriptor> queue;
queue.push_back(source);
// Bfs
while (!queue.empty()) {
TVertexDescriptor u = queue.front();
queue.pop_front();
typedef typename Iterator<Graph<TSpec>, OutEdgeIterator>::Type TOutEdgeIterator;
TOutEdgeIterator itout(g,u);
for(;!atEnd(itout);goNext(itout)) {
TVertexDescriptor v = targetVertex(itout);
if (getProperty(tokenMap, v) == false) {
assignProperty(tokenMap, v, true);
assignProperty(distance, v, getProperty(distance,u) + 1);
assignProperty(predecessor, v, u);
queue.push_back(v);
}
}
}
}
} // namespace seqan2
#endif // #ifndef INCLUDE_SEQAN_GRAPH_ALGORITHMS_BREADTH_FIRST_SEARCH_H_
|
