public bool TryGetSuccessor(IImplicitGraph <TVertex, TEdge> g, TVertex u, out TEdge successor)
{
Contract.Requires(g != null);
Contract.Requires(u != null);
int outDegree = g.OutDegree(u);
if (outDegree > 0)
{
int index;
if (!outEdgeIndices.TryGetValue(u, out index))
{
index = 0;
outEdgeIndices.Add(u, index);
}
TEdge e = g.OutEdge(u, index);
this.outEdgeIndices[u] = (++index) % outDegree;
successor = e;
return(true);
}
successor = default(TEdge);
return(false);
}
protected static void OutEdge_Test(
[NotNull] GraphData <int, Edge <int> > data,
[NotNull] IImplicitGraph <int, Edge <int> > graph)
{
var edge11 = new Edge <int>(1, 1);
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
data.CheckCalls(0);
data.ShouldReturnValue = true;
data.ShouldReturnEdges = new[] { edge11, edge12, edge13 };
Assert.AreSame(edge11, graph.OutEdge(1, 0));
data.CheckCalls(1);
Assert.AreSame(edge13, graph.OutEdge(1, 2));
data.CheckCalls(1);
}
protected static void OutEdge_NullThrows_Test <TVertex, TEdge>(
IImplicitGraph <TVertex, TEdge> graph)
where TVertex : class
where TEdge : IEdge <TVertex>
{
// ReSharper disable once ReturnValueOfPureMethodIsNotUsed
// ReSharper disable once AssignNullToNotNullAttribute
Assert.Throws <ArgumentNullException>(() => graph.OutEdge(null, 0));
}
protected static void OutEdge_Test(
IImplicitGraph <int, Edge <int> > graph,
Action <IEnumerable <Edge <int> > > addVerticesAndEdgeRange)
{
var edge11 = new Edge <int>(1, 1);
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge24 = new Edge <int>(2, 4);
var edge33 = new Edge <int>(3, 3);
var edge41 = new Edge <int>(4, 1);
addVerticesAndEdgeRange(new[] { edge11, edge12, edge13, edge24, edge33, edge41 });
Assert.AreSame(edge11, graph.OutEdge(1, 0));
Assert.AreSame(edge13, graph.OutEdge(1, 2));
Assert.AreSame(edge24, graph.OutEdge(2, 0));
Assert.AreSame(edge33, graph.OutEdge(3, 0));
Assert.AreSame(edge41, graph.OutEdge(4, 0));
}
protected static void OutEdge_Throws_Test(
IImplicitGraph <int, Edge <int> > graph,
Action <int> addVertex,
Action <Edge <int> > addEdge)
{
const int vertex1 = 1;
const int vertex2 = 2;
// ReSharper disable ReturnValueOfPureMethodIsNotUsed
Assert.Throws <VertexNotFoundException>(() => graph.OutEdge(vertex1, 0));
addVertex(vertex1);
addVertex(vertex2);
AssertIndexOutOfRange(() => graph.OutEdge(vertex1, 0));
addEdge(new Edge <int>(1, 2));
AssertIndexOutOfRange(() => graph.OutEdge(vertex1, 5));
// ReSharper restore ReturnValueOfPureMethodIsNotUsed
}
protected static void OutEdge_Throws_Test(
[NotNull] GraphData <int, Edge <int> > data,
[NotNull] IImplicitGraph <int, Edge <int> > graph)
{
// ReSharper disable ReturnValueOfPureMethodIsNotUsed
data.CheckCalls(0);
data.ShouldReturnValue = false;
Assert.Throws <VertexNotFoundException>(() => graph.OutEdge(1, 0));
data.CheckCalls(1);
data.ShouldReturnValue = true;
AssertIndexOutOfRange(() => graph.OutEdge(1, 0));
data.CheckCalls(1);
data.ShouldReturnEdges = new[] { new Edge <int>(1, 2) };
AssertIndexOutOfRange(() => graph.OutEdge(1, 1));
data.CheckCalls(1);
// ReSharper restore ReturnValueOfPureMethodIsNotUsed
}
protected static void OutEdge_ImmutableGraph_Test(
IMutableVertexAndEdgeSet <int, Edge <int> > wrappedGraph,
Func <IImplicitGraph <int, SEquatableEdge <int> > > createGraph)
{
var edge11 = new Edge <int>(1, 1);
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge24 = new Edge <int>(2, 4);
var edge33 = new Edge <int>(3, 3);
var edge41 = new Edge <int>(4, 1);
wrappedGraph.AddVerticesAndEdgeRange(new[] { edge11, edge12, edge13, edge24, edge33, edge41 });
IImplicitGraph <int, SEquatableEdge <int> > graph = createGraph();
Assert.AreEqual(new SEquatableEdge <int>(1, 1), graph.OutEdge(1, 0));
Assert.AreEqual(new SEquatableEdge <int>(1, 3), graph.OutEdge(1, 2));
Assert.AreEqual(new SEquatableEdge <int>(2, 4), graph.OutEdge(2, 0));
Assert.AreEqual(new SEquatableEdge <int>(3, 3), graph.OutEdge(3, 0));
Assert.AreEqual(new SEquatableEdge <int>(4, 1), graph.OutEdge(4, 0));
}
protected static void OutEdge_ImmutableGraph_Test(
[NotNull] IMutableVertexAndEdgeSet <int, Edge <int> > wrappedGraph,
[NotNull, InstantHandle] Func <IImplicitGraph <int, Edge <int> > > createGraph)
{
var edge11 = new Edge <int>(1, 1);
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge24 = new Edge <int>(2, 4);
var edge33 = new Edge <int>(3, 3);
var edge41 = new Edge <int>(4, 1);
wrappedGraph.AddVerticesAndEdgeRange(new[] { edge11, edge12, edge13, edge24, edge33, edge41 });
IImplicitGraph <int, Edge <int> > graph = createGraph();
Assert.AreSame(edge11, graph.OutEdge(1, 0));
Assert.AreSame(edge13, graph.OutEdge(1, 2));
Assert.AreSame(edge24, graph.OutEdge(2, 0));
Assert.AreSame(edge33, graph.OutEdge(3, 0));
Assert.AreSame(edge41, graph.OutEdge(4, 0));
}
protected static void OutEdge_Throws_ImmutableGraph_ReversedTest(
IMutableVertexAndEdgeSet <int, Edge <int> > wrappedGraph,
Func <IImplicitGraph <int, SReversedEdge <int, Edge <int> > > > createGraph)
{
IImplicitGraph <int, SReversedEdge <int, Edge <int> > > graph = createGraph();
const int vertex1 = 1;
const int vertex2 = 2;
// ReSharper disable ReturnValueOfPureMethodIsNotUsed
Assert.Throws <VertexNotFoundException>(() => graph.OutEdge(vertex1, 0));
wrappedGraph.AddVertex(vertex1);
wrappedGraph.AddVertex(vertex2);
graph = createGraph();
AssertIndexOutOfRange(() => graph.OutEdge(vertex1, 0));
wrappedGraph.AddEdge(new Edge <int>(1, 2));
graph = createGraph();
AssertIndexOutOfRange(() => graph.OutEdge(vertex1, 5));
// ReSharper restore ReturnValueOfPureMethodIsNotUsed
}
public override TEdge Successor(IImplicitGraph <TVertex, TEdge> g, TVertex u)
{
int outDegree = g.OutDegree(u);
if (outDegree == 0)
{
return(default(TEdge));
}
int index = this.Rand.Next(0, outDegree);
return(g.OutEdge(u, index));
}
/// <inheritdoc />
public override bool TryGetSuccessor(IImplicitGraph<TVertex, TEdge> graph, TVertex vertex, out TEdge successor)
{
int outDegree = graph.OutDegree(vertex);
if (outDegree > 0)
{
int index = Rand.Next(0, outDegree);
successor = graph.OutEdge(vertex, index);
return true;
}
successor = default(TEdge);
return false;
}
public override bool TryGetSuccessor(IImplicitGraph <TVertex, TEdge> g, TVertex u, out TEdge successor)
{
int outDegree = g.OutDegree(u);
if (outDegree > 0)
{
int index = this.Rand.Next(0, outDegree);
successor = g.OutEdge(u, index);
return(true);
}
successor = default(TEdge);
return(false);
}
protected static void OutEdge_Throws_ImmutableGraph_Test <TEdge>(
[NotNull] IMutableVertexAndEdgeSet <int, Edge <int> > wrappedGraph,
[NotNull, InstantHandle] Func <IImplicitGraph <int, TEdge> > createGraph)
where TEdge : IEdge <int>
{
IImplicitGraph <int, TEdge> graph = createGraph();
const int vertex1 = 1;
const int vertex2 = 2;
// ReSharper disable ReturnValueOfPureMethodIsNotUsed
Assert.Throws <VertexNotFoundException>(() => graph.OutEdge(vertex1, 0));
wrappedGraph.AddVertex(vertex1);
wrappedGraph.AddVertex(vertex2);
graph = createGraph();
AssertIndexOutOfRange(() => graph.OutEdge(vertex1, 0));
wrappedGraph.AddEdge(new Edge <int>(1, 2));
graph = createGraph();
AssertIndexOutOfRange(() => graph.OutEdge(vertex1, 5));
// ReSharper restore ReturnValueOfPureMethodIsNotUsed
}
/// <inheritdoc />
public bool TryGetSuccessor(IImplicitGraph <TVertex, TEdge> graph, TVertex vertex, out TEdge successor)
{
int outDegree = graph.OutDegree(vertex);
if (outDegree > 0)
{
if (!_outEdgeIndices.TryGetValue(vertex, out int index))
{
index = 0;
_outEdgeIndices.Add(vertex, index);
}
TEdge edge = graph.OutEdge(vertex, index);
_outEdgeIndices[vertex] = ++index % outDegree;
successor = edge;
return(true);
}
successor = default(TEdge);
return(false);
}
public TEdge Successor(IImplicitGraph <TVertex, TEdge> g, TVertex u)
{
int outDegree = g.OutDegree(u);
if (outDegree == 0)
{
return(default(TEdge));
}
int index;
if (!outEdgeIndices.TryGetValue(u, out index))
{
index = 0;
outEdgeIndices.Add(u, index);
}
TEdge e = g.OutEdge(u, index);
this.outEdgeIndices[u] = (++index) % outDegree;
return(e);
}
public Edge OutEdge(Vertex v, int index)
{
return(_impl.OutEdge(v, index));
}