public void SimpleGraph()
{
var graph = new UndirectedGraph <int, Edge <int> >();
graph.AddVerticesAndEdgeRange(new[]
{
new Edge <int>(1, 2),
new Edge <int>(2, 3),
new Edge <int>(4, 2),
new Edge <int>(4, 5),
new Edge <int>(5, 6),
new Edge <int>(7, 5),
new Edge <int>(7, 8)
});
var algorithm = new UndirectedFirstTopologicalSortAlgorithm <int, Edge <int> >(graph);
algorithm.Compute();
// Order in undirected graph is some strange thing, here the order
// is more vertices ordered from lower to higher adjacent vertices
CollectionAssert.AreEqual(
new[] { 1, 8, 3, 7, 2, 6, 4, 5 },
algorithm.SortedVertices);
}
public void GraphWithSelfEdge()
{
var graph = new UndirectedGraph <int, Edge <int> >();
graph.AddVerticesAndEdgeRange(new[]
{
new Edge <int>(0, 1),
new Edge <int>(1, 2),
new Edge <int>(1, 3),
new Edge <int>(2, 3),
new Edge <int>(2, 2),
new Edge <int>(3, 4)
});
var algorithm = new UndirectedFirstTopologicalSortAlgorithm <int, Edge <int> >(graph);
Assert.Throws <NonAcyclicGraphException>(() => algorithm.Compute());
algorithm = new UndirectedFirstTopologicalSortAlgorithm <int, Edge <int> >(graph)
{
AllowCyclicGraph = true
};
algorithm.Compute();
// Order in undirected graph is some strange thing, here the order
// is more vertices ordered from lower to higher adjacent vertices
CollectionAssert.AreEqual(
new[] { 0, 4, 1, 3, 2 },
algorithm.SortedVertices);
}
public void Constructor()
{
var graph = new UndirectedGraph <int, Edge <int> >();
var algorithm = new UndirectedFirstTopologicalSortAlgorithm <int, Edge <int> >(graph);
AssertAlgorithmProperties(algorithm, graph);
algorithm = new UndirectedFirstTopologicalSortAlgorithm <int, Edge <int> >(graph)
{
AllowCyclicGraph = true
};
AssertAlgorithmProperties(algorithm, graph, true);
algorithm = new UndirectedFirstTopologicalSortAlgorithm <int, Edge <int> >(graph, 0);
AssertAlgorithmProperties(algorithm, graph);
algorithm = new UndirectedFirstTopologicalSortAlgorithm <int, Edge <int> >(graph, 10);
AssertAlgorithmProperties(algorithm, graph);
#region Local function
void AssertAlgorithmProperties <TVertex, TEdge>(
UndirectedFirstTopologicalSortAlgorithm <TVertex, TEdge> algo,
IUndirectedGraph <TVertex, TEdge> g,
bool allowCycles = false)
where TEdge : IEdge <TVertex>
{
AssertAlgorithmState(algo, g);
Assert.IsNull(algo.SortedVertices);
CollectionAssert.IsEmpty(algo.Degrees);
Assert.AreEqual(allowCycles, algo.AllowCyclicGraph);
}
#endregion
}
public void Compute([PexAssumeNotNull]IUndirectedGraph<string, Edge<string>> g)
{
var topo =
new UndirectedFirstTopologicalSortAlgorithm<string, Edge<string>>(g);
topo.AllowCyclicGraph = true;
topo.Compute();
Display(topo);
}
private static void Compute <TVertex, TEdge>([NotNull] IUndirectedGraph <TVertex, TEdge> graph)
where TEdge : IEdge <TVertex>
{
var algorithm = new UndirectedFirstTopologicalSortAlgorithm <TVertex, TEdge>(graph)
{
AllowCyclicGraph = true
};
algorithm.Compute();
}
public static (int[], string) Get(UndirectedGraph <int, Edge <int> > graph)
{
var algorithm = new UndirectedFirstTopologicalSortAlgorithm <int, Edge <int> >(graph);
try
{
algorithm.Compute();
return(algorithm.SortedVertices, null);
}
catch (System.Exception ex)
{
return(null, ex.Message);
}
}
private static void RunUndirectedFirstTopologicalSortAndCheck <TVertex, TEdge>(
IUndirectedGraph <TVertex, TEdge> graph,
bool allowCycles)
where TEdge : IEdge <TVertex>
{
var algorithm = new UndirectedFirstTopologicalSortAlgorithm <TVertex, TEdge>(graph)
{
AllowCyclicGraph = allowCycles
};
algorithm.Compute();
Assert.IsNotNull(algorithm.SortedVertices);
Assert.AreEqual(graph.VertexCount, algorithm.SortedVertices.Length);
Assert.IsNotNull(algorithm.Degrees);
Assert.AreEqual(graph.VertexCount, algorithm.Degrees.Count);
}
public void UndirectedFirstTopologicalSort_Throws()
{
var cyclicGraph = new UndirectedGraph <int, Edge <int> >();
cyclicGraph.AddVerticesAndEdgeRange(new[]
{
new Edge <int>(1, 2),
new Edge <int>(2, 3),
new Edge <int>(1, 4),
new Edge <int>(3, 1)
});
var algorithm = new UndirectedFirstTopologicalSortAlgorithm <int, Edge <int> >(cyclicGraph);
Assert.Throws <NonAcyclicGraphException>(() => algorithm.Compute());
algorithm = new UndirectedFirstTopologicalSortAlgorithm <int, Edge <int> >(cyclicGraph)
{
AllowCyclicGraph = true
};
Assert.DoesNotThrow(() => algorithm.Compute());
}
private void Display(UndirectedFirstTopologicalSortAlgorithm<string, Edge<string>> topo)
{
int index = 0;
foreach (string v in topo.SortedVertices)
Console.WriteLine("{0}: {1}", index++, v);
}
