Example Program
Shortest Path in DAGs
Computing single source shortest paths in a directed acyclic graph.
File "graph_algo_path_dag.cpp"
A tutorial about a shortest path search in a directed acyclic graph.

1 | #include <iostream>
2 | #include <seqan/graph_algorithms.h>
3 |
4 | using namespace seqan;
5 |
6 | int main() {
7 | typedef Graph<Directed<> > TGraph;
8 | typedef VertexDescriptor<TGraph>::Type TVertexDescriptor;
9 | typedef EdgeDescriptor<TGraph>::Type TEdgeDescriptor;
10 | typedef Size<TGraph>::Type TSize;

Graph creation: 10 directed edges (0,2), (0,1), ...

11 | TSize numEdges = 10;
12 | TVertexDescriptor edges[] = {0,2, 0,1, 1,3, 1,2, 2,5, 2,4, 2,3, 3,5, 3,4, 4,5};
13 | TGraph g;
14 | addEdges(g, edges, numEdges);
15 | ::std::cout << g << ::std::endl;

One external property map: Weight map

16 | int weights[] = {3, 5, 6, 2, 2, 4, 7, 1, -1, -2};
17 | String<int> weightMap;
18 | resizeEdgeMap(g,weightMap, weights);

Out-parameters: Predecessor and distance map

19 | String<unsigned int> predMap;
20 | String<unsigned int> distMap;

DAG-Shortest path from vertex 1

21 | dagShortestPath(g,1,weightMap,predMap,distMap);

Console Output

22 | ::std::cout << "Single-Source Shortest Paths in DAG: " << ::std::endl;
23 | typedef Iterator<TGraph, VertexIterator>::Type TVertexIterator;
24 | TVertexIterator it(g);
25 | while(!atEnd(it)) {
26 | ::std::cout << "Path from 1 to " << getValue(it) << ": ";
27 | _printPath(g,predMap,(TVertexDescriptor) 1, getValue(it));
28 | ::std::cout << " (Distance: " << getProperty(distMap, getValue(it)) << ")" << ::std::endl;
29 | goNext(it);
30 | }
31 | return 0;
32 | }

See
Graph, dagShortestPath
SeqAn - Sequence Analysis Library - www.seqan.de

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