fn()dagShortestPathComputes shortest paths from a single source in a directed acyclic graph (DAG).

Defined in ```void dagShortestPath(predecessor, distance, g, source, weight); ```

Parameters

 `predecessor` A property map. A property map that represents predecessor relationships among vertices. It determines a shortest-paths tree. A property map. Indicates for each vertex th distance from the source. do exist. A directed acyclic graph. Types: Directed Graph A source vertex. Types: VertexDescriptor A weight map. In a directed acyclic graph edge weights can be negative because no cycles

Detailed Description

Example

```#include <iostream>
#include <seqan/graph_algorithms.h>

using namespace seqan;

int main()
{
typedef Graph<Directed<> > TGraph;
typedef VertexDescriptor<TGraph>::Type TVertexDescriptor;
typedef Size<TGraph>::Type TSize;

// Create graph with 10 directed edges (0,2), (0,1), ...
TSize numEdges = 10;
TVertexDescriptor edges[] = {0, 2, 0, 1, 1, 3, 1, 2, 2, 5, 2, 4, 2, 3, 3, 5, 3, 4, 4, 5};
TGraph g;
// Print graph to stdout.
std::cout << g << "\n";

// Create external edge property map with edge weights.
int weights[] = {3, 5, 6, 2, 2, 4, 7, 1, -1, -2};
String<int> weightMap;
assignEdgeMap(weightMap, g, weights);

// Run DAG shortest path computation from vertex with descriptor 1.
String<unsigned> predMap;
String<unsigned> distMap;
dagShortestPath(predMap, distMap, g, 1, weightMap);

// Print result to stdout.
std::cout << "Single-Source Shortest Paths in DAG: \n";
typedef Iterator<TGraph, VertexIterator>::Type TVertexIterator;
TVertexIterator it(g);
while (!atEnd(it))
{
std::cout << "Path from 1 to " << getValue(it) << ": ";
_printPath(g, predMap, (TVertexDescriptor)1, getValue(it));
std::cout << " (Distance: " << getProperty(distMap, getValue(it)) << ")\n";
goNext(it);
}

return 0;
}
```
```Adjacency list:
0 -> 1,2,
1 -> 2,3,
2 -> 3,4,5,
3 -> 4,5,
4 -> 5,
5 ->
Edge list:
Source: 0,Target: 1 (Id: 1)
Source: 0,Target: 2 (Id: 0)
Source: 1,Target: 2 (Id: 3)
Source: 1,Target: 3 (Id: 2)
Source: 2,Target: 3 (Id: 6)
Source: 2,Target: 4 (Id: 5)
Source: 2,Target: 5 (Id: 4)
Source: 3,Target: 4 (Id: 8)
Source: 3,Target: 5 (Id: 7)
Source: 4,Target: 5 (Id: 9)

Single-Source Shortest Paths in DAG:
Path from 1 to 0: No path from 1 to 0 exists. (Distance: 1073741823)
Path from 1 to 1: 1 (Distance: 0)
Path from 1 to 2: 1,2 (Distance: 2)
Path from 1 to 3: 1,3 (Distance: 6)
Path from 1 to 4: 1,3,4 (Distance: 5)
Path from 1 to 5: 1,3,4,5 (Distance: 3)
```