private readonly Edge[] _edgeTo; // edgeTo[v] = last edge on longest s->v path.
public AcyclicLongestPath(EdgeWeightedDigraph graph, Int32 vertice)
{
this._distTo = new Double[graph.VerticesCount];
this._edgeTo = new Edge[graph.VerticesCount];
for (int i = 0; i < graph.VerticesCount; i++)
{
this._distTo[i] = Double.NegativeInfinity;
}
this._distTo[vertice] = 0.0;
TopologicalChecker topological = TopologicalChecker.Create(graph);
if (topological.Order == null)
{
throw new InvalidOperationException("Digraph is not acyclic.");
}
foreach (Int32 v in topological.Order)
{
foreach (Edge edge in graph.GetAdjacentVertices(v))
{
this.Relax(edge);
}
}
}
public void Test_IsDAG_EdgeWeighted()
{
EdgeWeightedDigraph graph = new EdgeWeightedDigraph(3);
graph.AddEdge(new Edge(0, 1, 0.2));
graph.AddEdge(new Edge(0, 2, 0.3));
TopologicalChecker checker = TopologicalChecker.Create(graph);
Assert.True(checker.IsDAG);
}
public void Test_IsDAG()
{
Digraph graph = new Digraph(3);
graph.AddEdge(0, 1);
graph.AddEdge(0, 2);
TopologicalChecker checker = TopologicalChecker.Create(graph);
Assert.True(checker.IsDAG);
}
public void Test_Rank()
{
Digraph graph = new Digraph(4);
graph.AddEdge(0, 1);
graph.AddEdge(0, 2);
graph.AddEdge(2, 3);
TopologicalChecker checker = TopologicalChecker.Create(graph);
Assert.Equal(1, checker.Rank(1));
}
public void Test_Order()
{
Digraph graph = new Digraph(4);
graph.AddEdge(0, 1);
graph.AddEdge(0, 2);
graph.AddEdge(2, 3);
TopologicalChecker checker = TopologicalChecker.Create(graph);
AssertUtilities.Sequence(new Int32[4] {
0, 1, 2, 3
}, checker.Order);
}
