private static void RunEdgeDFSAndCheck <TVertex, TEdge>(
[NotNull] IEdgeListAndIncidenceGraph <TVertex, TEdge> graph,
int maxDepth = int.MaxValue)
where TEdge : IEdge <TVertex>
{
var parents = new Dictionary <TEdge, TEdge>();
var discoverTimes = new Dictionary <TEdge, int>();
var finishTimes = new Dictionary <TEdge, int>();
int time = 0;
var dfs = new EdgeDepthFirstSearchAlgorithm <TVertex, TEdge>(graph)
{
MaxDepth = maxDepth
};
dfs.InitializeEdge += edge =>
{
Assert.AreEqual(GraphColor.White, dfs.EdgesColors[edge]);
};
dfs.StartEdge += edge =>
{
Assert.AreEqual(GraphColor.White, dfs.EdgesColors[edge]);
Assert.IsFalse(parents.ContainsKey(edge));
parents[edge] = edge;
discoverTimes[edge] = time++;
};
dfs.DiscoverTreeEdge += (edge, targetEdge) =>
{
parents[targetEdge] = edge;
Assert.AreEqual(GraphColor.White, dfs.EdgesColors[targetEdge]);
Assert.AreEqual(GraphColor.Gray, dfs.EdgesColors[parents[targetEdge]]);
discoverTimes[targetEdge] = time++;
};
dfs.TreeEdge += edge =>
{
Assert.AreEqual(GraphColor.Gray, dfs.EdgesColors[edge]);
};
dfs.BackEdge += edge =>
{
Assert.AreEqual(GraphColor.Gray, dfs.EdgesColors[edge]);
};
dfs.ForwardOrCrossEdge += edge =>
{
Assert.AreEqual(GraphColor.Black, dfs.EdgesColors[edge]);
};
dfs.FinishEdge += edge =>
{
Assert.AreEqual(GraphColor.Black, dfs.EdgesColors[edge]);
finishTimes[edge] = time++;
};
dfs.Compute();
// Check
// All vertices should be black
foreach (TEdge edge in graph.Edges)
{
Assert.IsTrue(dfs.EdgesColors.ContainsKey(edge));
Assert.AreEqual(dfs.EdgesColors[edge], GraphColor.Black);
}
foreach (TEdge e1 in graph.Edges)
{
foreach (TEdge e2 in graph.Edges)
{
if (!e1.Equals(e2))
{
Assert.IsTrue(
finishTimes[e1] < discoverTimes[e2] ||
finishTimes[e2] < discoverTimes[e1] ||
(discoverTimes[e2] < discoverTimes[e1] && finishTimes[e1] < finishTimes[e2] && IsDescendant(parents, e1, e2)) ||
(discoverTimes[e1] < discoverTimes[e2] && finishTimes[e2] < finishTimes[e1] && IsDescendant(parents, e2, e1)));
}
}
}
}
public void AllMergedPath()
{
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
var graph = new AdjacencyGraph <int, Edge <int> >();
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
CollectionAssert.IsEmpty(recorder.AllMergedPaths());
}
}
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
// Graph without cycle
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge14 = new Edge <int>(1, 4);
var edge24 = new Edge <int>(2, 4);
var edge31 = new Edge <int>(3, 1);
var edge33 = new Edge <int>(3, 3);
var edge34 = new Edge <int>(3, 4);
var graph = new AdjacencyGraph <int, Edge <int> >();
graph.AddVerticesAndEdgeRange(new[]
{
edge12, edge13, edge14, edge24, edge31, edge33, edge34
});
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
CollectionAssert.AreEquivalent(
new IEnumerable <Edge <int> >[]
{
new[] { edge12, edge24 },
new[] { edge13, edge31, edge14 },
new[] { /* edge13 can't be reused */ edge33, edge34 }
},
recorder.AllMergedPaths());
}
}
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
// Graph with cycle
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge14 = new Edge <int>(1, 4);
var edge24 = new Edge <int>(2, 4);
var edge31 = new Edge <int>(3, 1);
var edge33 = new Edge <int>(3, 3);
var edge34 = new Edge <int>(3, 4);
var edge41 = new Edge <int>(4, 1);
var graph = new AdjacencyGraph <int, Edge <int> >();
graph.AddVerticesAndEdgeRange(new[]
{
edge12, edge13, edge14, edge24, edge31, edge33, edge34, edge41
});
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
CollectionAssert.AreEquivalent(
new IEnumerable <Edge <int> >[]
{
new[] { edge12, edge24, edge41, edge13, edge31, edge14 },
new[] { /* edge12, edge24, edge41, edge13 can't be reused */ edge33, edge34 }
},
recorder.AllMergedPaths());
}
}
}
public void MergedPath()
{
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
var graph = new AdjacencyGraph <int, Edge <int> >();
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
var edge12 = new Edge <int>(1, 2);
var colors = new Dictionary <Edge <int>, GraphColor>
{
[edge12] = GraphColor.Black
};
// Not in the graph and edge marked as already used!
CollectionAssert.IsEmpty(recorder.MergedPath(edge12, colors));
// Not in the graph => return the edge itself
colors[edge12] = GraphColor.White;
CollectionAssert.AreEqual(
new[] { edge12 },
recorder.MergedPath(edge12, colors));
}
}
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
// Graph without cycle
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge14 = new Edge <int>(1, 4);
var edge24 = new Edge <int>(2, 4);
var edge31 = new Edge <int>(3, 1);
var edge33 = new Edge <int>(3, 3);
var edge34 = new Edge <int>(3, 4);
var graph = new AdjacencyGraph <int, Edge <int> >();
graph.AddVerticesAndEdgeRange(new[]
{
edge12, edge13, edge14, edge24, edge31, edge33, edge34
});
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
Dictionary <Edge <int>, GraphColor> colors = graph.Edges.ToDictionary(
edge => edge,
_ => GraphColor.White);
CollectionAssert.AreEqual(
new[] { edge12, edge24 },
recorder.MergedPath(edge24, colors));
// Already used
CollectionAssert.IsEmpty(recorder.MergedPath(edge24, colors));
CollectionAssert.AreEqual(
new[] { edge13, edge31 },
recorder.MergedPath(edge31, colors));
}
}
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
// Graph with cycle
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge14 = new Edge <int>(1, 4);
var edge24 = new Edge <int>(2, 4);
var edge31 = new Edge <int>(3, 1);
var edge33 = new Edge <int>(3, 3);
var edge34 = new Edge <int>(3, 4);
var edge41 = new Edge <int>(4, 1);
var graph = new AdjacencyGraph <int, Edge <int> >();
graph.AddVerticesAndEdgeRange(new[]
{
edge12, edge13, edge14, edge24, edge31, edge33, edge34, edge41
});
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
Dictionary <Edge <int>, GraphColor> colors = graph.Edges.ToDictionary(
edge => edge,
_ => GraphColor.White);
CollectionAssert.AreEqual(
new[] { edge12, edge24, edge41 },
recorder.MergedPath(edge41, colors));
// Already used
CollectionAssert.IsEmpty(recorder.MergedPath(edge41, colors));
CollectionAssert.AreEqual(
new[] { edge13, edge33, edge34 },
recorder.MergedPath(edge34, colors));
}
}
}
public void Attach()
{
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
var graph = new AdjacencyGraph <int, Edge <int> >();
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
CollectionAssert.IsEmpty(recorder.EdgesPredecessors);
CollectionAssert.IsEmpty(recorder.EndPathEdges);
}
}
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
var graph = new AdjacencyGraph <int, Edge <int> >();
graph.AddVertexRange(new[] { 1, 2 });
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
CollectionAssert.IsEmpty(recorder.EdgesPredecessors);
CollectionAssert.IsEmpty(recorder.EndPathEdges);
}
}
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
// Graph without cycle
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge14 = new Edge <int>(1, 4);
var edge24 = new Edge <int>(2, 4);
var edge31 = new Edge <int>(3, 1);
var edge33 = new Edge <int>(3, 3);
var edge34 = new Edge <int>(3, 4);
var graph = new AdjacencyGraph <int, Edge <int> >();
graph.AddVerticesAndEdgeRange(new[]
{
edge12, edge13, edge14, edge24, edge31, edge33, edge34
});
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
CollectionAssert.AreEqual(
new Dictionary <Edge <int>, Edge <int> >
{
[edge14] = edge31,
[edge24] = edge12,
[edge31] = edge13,
[edge33] = edge13,
[edge34] = edge33
},
recorder.EdgesPredecessors);
CollectionAssert.AreEquivalent(
new[] { edge14, edge24, edge34 },
recorder.EndPathEdges);
}
}
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
// Graph with cycle
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge14 = new Edge <int>(1, 4);
var edge24 = new Edge <int>(2, 4);
var edge31 = new Edge <int>(3, 1);
var edge33 = new Edge <int>(3, 3);
var edge34 = new Edge <int>(3, 4);
var edge41 = new Edge <int>(4, 1);
var graph = new AdjacencyGraph <int, Edge <int> >();
graph.AddVerticesAndEdgeRange(new[]
{
edge12, edge13, edge14, edge24, edge31, edge33, edge34, edge41
});
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
CollectionAssert.AreEqual(
new Dictionary <Edge <int>, Edge <int> >
{
[edge13] = edge41,
[edge14] = edge31,
[edge24] = edge12,
[edge31] = edge13,
[edge33] = edge13,
[edge34] = edge33,
[edge41] = edge24
},
recorder.EdgesPredecessors);
CollectionAssert.AreEquivalent(
new[] { edge14, edge34 },
recorder.EndPathEdges);
}
}
}
public void Path()
{
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
var graph = new AdjacencyGraph <int, Edge <int> >();
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
var edge12 = new Edge <int>(1, 2);
// Not in the graph => return the edge itself
CollectionAssert.AreEqual(
new[] { edge12 },
recorder.Path(edge12));
}
}
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
// Graph without cycle
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge14 = new Edge <int>(1, 4);
var edge24 = new Edge <int>(2, 4);
var edge31 = new Edge <int>(3, 1);
var edge33 = new Edge <int>(3, 3);
var edge34 = new Edge <int>(3, 4);
var graph = new AdjacencyGraph <int, Edge <int> >();
graph.AddVerticesAndEdgeRange(new[]
{
edge12, edge13, edge14, edge24, edge31, edge33, edge34
});
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
CollectionAssert.AreEquivalent(
new[] { edge13, edge31, edge14 },
recorder.Path(edge14));
CollectionAssert.AreEquivalent(
new[] { edge13, edge33 },
recorder.Path(edge33));
}
}
{
var recorder = new EdgePredecessorRecorderObserver <int, Edge <int> >();
// Graph with cycle
var edge12 = new Edge <int>(1, 2);
var edge13 = new Edge <int>(1, 3);
var edge14 = new Edge <int>(1, 4);
var edge24 = new Edge <int>(2, 4);
var edge31 = new Edge <int>(3, 1);
var edge33 = new Edge <int>(3, 3);
var edge34 = new Edge <int>(3, 4);
var edge41 = new Edge <int>(4, 1);
var graph = new AdjacencyGraph <int, Edge <int> >();
graph.AddVerticesAndEdgeRange(new[]
{
edge12, edge13, edge14, edge24, edge31, edge33, edge34, edge41
});
var dfs = new EdgeDepthFirstSearchAlgorithm <int, Edge <int> >(graph);
using (recorder.Attach(dfs))
{
dfs.Compute();
CollectionAssert.AreEquivalent(
new[] { edge12, edge24, edge41, edge13, edge31, edge14 },
recorder.Path(edge14));
CollectionAssert.AreEquivalent(
new[] { edge12, edge24, edge41, edge13, edge33 },
recorder.Path(edge33));
}
}
}
