public void FindSet()
{
FindSetTest(1, 2);
FindSetTest(
new TestVertex("1"),
new TestVertex("2"));
FindSetTest(
new EquatableTestVertex("1"),
new EquatableTestVertex("2"));
#region Local function
void FindSetTest <TValue>(TValue value1, TValue value2)
{
var set = new ForestDisjointSet <TValue>();
AssertSetSizes(set, 0, 0);
set.MakeSet(value1);
AssertSetSizes(set, 1, 1);
AssertEqual(value1, set.FindSet(value1));
set.MakeSet(value2);
AssertSetSizes(set, 2, 2);
AssertEqual(value1, set.FindSet(value1));
AssertEqual(value2, set.FindSet(value2));
set.Union(value1, value2);
AssertSetSizes(set, 1, 2);
AssertEqual(value1, set.FindSet(value1));
AssertEqual(value1, set.FindSet(value2));
}
#endregion
}
public void Contains()
{
ContainsTest(1, 2);
ContainsTest(
new TestVertex("1"),
new TestVertex("2"));
ContainsTest(
new EquatableTestVertex("1"),
new EquatableTestVertex("2"));
#region Local function
void ContainsTest <TValue>(TValue value1, TValue value2)
{
var set = new ForestDisjointSet <TValue>();
Assert.IsFalse(set.Contains(value1));
Assert.IsFalse(set.Contains(value2));
set.MakeSet(value1);
Assert.IsTrue(set.Contains(value1));
Assert.IsFalse(set.Contains(value2));
set.MakeSet(value2);
Assert.IsTrue(set.Contains(value1));
Assert.IsTrue(set.Contains(value2));
set.Union(value1, value2);
Assert.IsTrue(set.Contains(value1));
Assert.IsTrue(set.Contains(value2));
}
#endregion
}
public void MakeSet_Throws()
{
var testObject = new TestVertex();
var set = new ForestDisjointSet <TestVertex>();
// ReSharper disable once AssignNullToNotNullAttribute
Assert.Throws <ArgumentNullException>(() => set.MakeSet(null));
set.MakeSet(testObject);
// Double insert
Assert.Throws <ArgumentException>(() => set.MakeSet(testObject));
}
/// <inheritdoc />
protected override void InternalCompute()
{
_sets = new ForestDisjointSet <TVertex>(VisitedGraph.VertexCount);
// Initialize one set per vertex
foreach (TVertex vertex in VisitedGraph.Vertices)
{
_sets.MakeSet(vertex);
}
// Join existing edges
foreach (TEdge edge in VisitedGraph.Edges)
{
_sets.Union(edge.Source, edge.Target);
}
// Hook to graph event
if (_hooked)
{
return;
}
VisitedGraph.EdgeAdded += OnEdgeAdded;
VisitedGraph.EdgeRemoved += OnEdgeRemoved;
VisitedGraph.VertexAdded += OnVertexAdded;
VisitedGraph.VertexRemoved += OnVertexRemoved;
_hooked = true;
}
protected override void InternalCompute()
{
var cancelManager = this.Services.CancelManager;
var ds = new ForestDisjointSet<TVertex>(this.VisitedGraph.VertexCount);
foreach (var v in this.VisitedGraph.Vertices)
ds.MakeSet(v);
if (cancelManager.IsCancelling)
return;
var queue = new BinaryQueue<TEdge, double>(this.edgeWeights);
foreach (var e in this.VisitedGraph.Edges)
queue.Enqueue(e);
if (cancelManager.IsCancelling)
return;
while (queue.Count > 0)
{
var e = queue.Dequeue();
this.OnExamineEdge(e);
if (!ds.AreInSameSet(e.Source, e.Target))
{
this.OnTreeEdge(e);
ds.Union(e.Source, e.Target);
}
}
}
/// <inheritdoc />
protected override void InternalCompute()
{
var sets = new ForestDisjointSet <TVertex>(VisitedGraph.VertexCount);
foreach (TVertex vertex in VisitedGraph.Vertices)
{
sets.MakeSet(vertex);
}
ThrowIfCancellationRequested();
var queue = new BinaryQueue <TEdge, double>(_edgeWeights);
foreach (TEdge edge in VisitedGraph.Edges)
{
queue.Enqueue(edge);
}
ThrowIfCancellationRequested();
while (queue.Count > 0)
{
TEdge edge = queue.Dequeue();
OnExamineEdge(edge);
if (!sets.AreInSameSet(edge.Source, edge.Target))
{
OnTreeEdge(edge);
sets.Union(edge.Source, edge.Target);
}
}
}
public void Union_Throws()
{
var vertex = new TestVertex("1");
var vertex2 = new TestVertex("2");
var set = new ForestDisjointSet <TestVertex>();
// ReSharper disable ReturnValueOfPureMethodIsNotUsed
// ReSharper disable AssignNullToNotNullAttribute
Assert.Throws <ArgumentNullException>(() => set.Union(vertex, null));
Assert.Throws <ArgumentNullException>(() => set.Union(null, vertex));
Assert.Throws <ArgumentNullException>(() => set.Union(null, null));
// ReSharper restore AssignNullToNotNullAttribute
Assert.Throws <KeyNotFoundException>(() => set.Union(vertex, vertex));
Assert.Throws <KeyNotFoundException>(() => set.Union(vertex, vertex2));
Assert.Throws <KeyNotFoundException>(() => set.Union(vertex2, vertex));
Assert.Throws <KeyNotFoundException>(() => set.Union(vertex2, vertex2));
set.MakeSet(vertex);
Assert.DoesNotThrow(() => set.Union(vertex, vertex));
Assert.Throws <KeyNotFoundException>(() => set.Union(vertex, vertex2));
Assert.Throws <KeyNotFoundException>(() => set.Union(vertex2, vertex));
Assert.Throws <KeyNotFoundException>(() => set.Union(vertex2, vertex2));
// ReSharper restore ReturnValueOfPureMethodIsNotUsed
}
protected static UndirectedGraph <string, TaggedEdge <string, double> > GetUndirectedCompleteGraph(int vertex)
{
var random = new Random();
var graph = new UndirectedGraph <string, TaggedEdge <string, double> >();
var trueGraph = new UndirectedGraph <string, TaggedEdge <string, double> >();
var sets = new ForestDisjointSet <string>(vertex);
for (int i = 0; i < vertex; ++i)
{
graph.AddVertex(i.ToString());
trueGraph.AddVertex(i.ToString());
sets.MakeSet(i.ToString());
}
for (int i = 0; i < vertex; ++i)
{
for (int j = i + 1; j < vertex; ++j)
{
graph.AddEdge(
new TaggedEdge <string, double>(
i.ToString(),
j.ToString(),
random.Next(100)));
}
}
return(graph);
}
public void Unions(int elementCount, [PexAssumeNotNull]KeyValuePair<int,int>[] unions)
{
PexAssume.IsTrue(0 < elementCount);
PexSymbolicValue.Minimize(elementCount);
PexAssume.TrueForAll(
unions,
u => 0 <= u.Key && u.Key < elementCount &&
0 <= u.Value && u.Value < elementCount
);
var target = new ForestDisjointSet<int>();
// fill up with 0..elementCount - 1
for (int i = 0; i < elementCount; i++)
{
target.MakeSet(i);
Assert.IsTrue(target.Contains(i));
Assert.AreEqual(i + 1, target.ElementCount);
Assert.AreEqual(i + 1, target.SetCount);
}
// apply Union for pairs unions[i], unions[i+1]
for (int i = 0; i < unions.Length; i++)
{
var left = unions[i].Key;
var right= unions[i].Value;
var setCount = target.SetCount;
bool unioned = target.Union(left, right);
// should be in the same set now
Assert.IsTrue(target.AreInSameSet(left, right));
// if unioned, the count decreased by 1
PexAssert.ImpliesIsTrue(unioned, () => setCount - 1 == target.SetCount);
}
}
public static ForestDisjointSet<int> Create(int[] elements, int[] unions)
{
var ds = new ForestDisjointSet<int>();
for (int i = 0; i < elements.Length; ++i)
ds.MakeSet(i);
for (int i = 0; i+1 < unions.Length; i+=2)
{
PexAssume.IsTrue(ds.Contains(unions[i]));
PexAssume.IsTrue(ds.Contains(unions[i+1]));
ds.Union(unions[i], unions[i+1]);
}
return ds;
}
public void AreInSameSet()
{
AreInSameSetTest(1, 2);
AreInSameSetTest(
new TestVertex("1"),
new TestVertex("2"));
AreInSameSetTest(
new EquatableTestVertex("1"),
new EquatableTestVertex("2"));
#region Local function
void AreInSameSetTest <TValue>(TValue value1, TValue value2)
{
var set = new ForestDisjointSet <TValue>();
AssertSetSizes(set, 0, 0);
set.MakeSet(value1);
Assert.IsTrue(set.AreInSameSet(value1, value1));
set.MakeSet(value2);
Assert.IsTrue(set.AreInSameSet(value1, value1));
Assert.IsFalse(set.AreInSameSet(value1, value2));
Assert.IsFalse(set.AreInSameSet(value2, value1));
Assert.IsTrue(set.AreInSameSet(value2, value2));
set.Union(value1, value2);
Assert.IsTrue(set.AreInSameSet(value1, value1));
Assert.IsTrue(set.AreInSameSet(value1, value2));
Assert.IsTrue(set.AreInSameSet(value2, value1));
Assert.IsTrue(set.AreInSameSet(value2, value2));
}
#endregion
}
/// <inheritdoc />
protected override void InternalCompute()
{
if (!TryGetRootVertex(out TVertex root))
{
throw new InvalidOperationException("Root vertex not set.");
}
if (_pairs is null)
{
throw new InvalidProgramException("Pairs not set.");
}
var graph = _pairs.ToAdjacencyGraph();
var disjointSet = new ForestDisjointSet <TVertex>();
var verticesAncestors = new Dictionary <TVertex, TVertex>();
var dfs = new DepthFirstSearchAlgorithm <TVertex, TEdge>(
this,
VisitedGraph,
new Dictionary <TVertex, GraphColor>(VisitedGraph.VertexCount));
dfs.InitializeVertex += vertex => disjointSet.MakeSet(vertex);
dfs.DiscoverVertex += vertex => verticesAncestors[vertex] = vertex;
dfs.TreeEdge += edge =>
{
disjointSet.Union(edge.Source, edge.Target);
// ReSharper disable once AssignNullToNotNullAttribute
// Justification: must be in the set because unioned just before.
verticesAncestors[disjointSet.FindSet(edge.Source)] = edge.Source;
};
dfs.FinishVertex += vertex =>
{
foreach (SEquatableEdge <TVertex> edge in graph.OutEdges(vertex))
{
if (dfs.VerticesColors[edge.Target] == GraphColor.Black)
{
SEquatableEdge <TVertex> pair = edge.ToVertexPair();
// ReSharper disable once AssignNullToNotNullAttribute
// Justification: must be present in the set.
Ancestors[pair] = verticesAncestors[disjointSet.FindSet(edge.Target)];
}
}
};
// Run DFS
dfs.Compute(root);
}
public static ForestDisjointSet <int> Create([NotNull] int[] elements, [NotNull] int[] unions)
{
var sets = new ForestDisjointSet <int>();
for (int i = 0; i < elements.Length; ++i)
{
sets.MakeSet(i);
}
for (int i = 0; i + 1 < unions.Length; i += 2)
{
Assert.IsTrue(sets.Contains(unions[i]));
Assert.IsTrue(sets.Contains(unions[i + 1]));
sets.Union(unions[i], unions[i + 1]);
}
return(sets);
}
public static IDisjointSet <TVertex> ComputeDisjointSet <TVertex, TEdge>(this IUndirectedGraph <TVertex, TEdge> visitedGraph)
where TEdge : IEdge <TVertex>
{
Contract.Requires(visitedGraph != null);
var ds = new ForestDisjointSet <TVertex>(visitedGraph.VertexCount);
foreach (var v in visitedGraph.Vertices)
{
ds.MakeSet(v);
}
foreach (var e in visitedGraph.Edges)
{
ds.Union(e.Source, e.Target);
}
return(ds);
}
protected override void InternalCompute()
{
var cancelManager = this.Services.CancelManager;
TVertex root;
if (!this.TryGetRootVertex(out root))
{
throw new InvalidOperationException("root vertex not set");
}
if (this.pairs == null)
{
throw new InvalidOperationException("pairs not set");
}
var gpair = GraphExtensions.ToAdjacencyGraph(this.pairs);
var disjointSet = new ForestDisjointSet <TVertex>();
var vancestors = new Dictionary <TVertex, TVertex>();
var dfs = new DepthFirstSearchAlgorithm <TVertex, TEdge>(this, this.VisitedGraph, new Dictionary <TVertex, GraphColor>(this.VisitedGraph.VertexCount));
dfs.InitializeVertex += v => disjointSet.MakeSet(v);
dfs.DiscoverVertex += v => vancestors[v] = v;
dfs.TreeEdge += edge =>
{
disjointSet.Union(edge.Source, edge.Target);
vancestors[disjointSet.FindSet(edge.Source)] = edge.Source;
};
dfs.FinishVertex += v =>
{
foreach (var e in gpair.OutEdges(v))
{
if (dfs.VertexColors[e.Target] == GraphColor.Black)
{
this.ancestors[EdgeExtensions.ToVertexPair <TVertex, SEquatableEdge <TVertex> >(e)] = vancestors[disjointSet.FindSet(e.Target)];
}
}
};
// go!
dfs.Compute(root);
}
/// <inheritdoc />
protected override void InternalCompute()
{
ICancelManager cancelManager = Services.CancelManager;
var sets = new ForestDisjointSet <TVertex>(VisitedGraph.VertexCount);
foreach (TVertex vertex in VisitedGraph.Vertices)
{
sets.MakeSet(vertex);
}
if (cancelManager.IsCancelling)
{
return;
}
var queue = new BinaryQueue <TEdge, double>(_edgeWeights);
foreach (TEdge edge in VisitedGraph.Edges)
{
queue.Enqueue(edge);
}
if (cancelManager.IsCancelling)
{
return;
}
while (queue.Count > 0)
{
TEdge edge = queue.Dequeue();
OnExamineEdge(edge);
if (!sets.AreInSameSet(edge.Source, edge.Target))
{
OnTreeEdge(edge);
sets.Union(edge.Source, edge.Target);
}
}
}
private void InitializeVerticesToEdges()
{
_verticesEdges = new Dictionary <TVertex, HashSet <TEdge> >();
_visitedVertices = new HashSet <TVertex>();
_sets = new ForestDisjointSet <TVertex>(VisitedGraph.VertexCount);
foreach (TVertex vertex in VisitedGraph.Vertices)
{
if (_visitedVertices.Count == 0)
{
_visitedVertices.Add(vertex);
}
_sets.MakeSet(vertex);
_verticesEdges.Add(vertex, new HashSet <TEdge>());
}
foreach (TEdge edge in VisitedGraph.Edges)
{
_verticesEdges[edge.Source].Add(edge);
_verticesEdges[edge.Target].Add(edge);
}
}
private void Unions(int elementCount, [NotNull] KeyValuePair <int, int>[] unions)
{
Assert.IsTrue(0 < elementCount);
QuikGraphAssert.TrueForAll(
unions,
u => 0 <= u.Key &&
u.Key < elementCount &&
0 <= u.Value &&
u.Value < elementCount);
var target = new ForestDisjointSet <int>();
// Fill up with 0..elementCount - 1
for (int i = 0; i < elementCount; ++i)
{
target.MakeSet(i);
Assert.IsTrue(target.Contains(i));
Assert.AreEqual(i + 1, target.ElementCount);
Assert.AreEqual(i + 1, target.SetCount);
}
// Apply Union for pairs unions[i], unions[i+1]
foreach (KeyValuePair <int, int> pair in unions)
{
int left = pair.Key;
int right = pair.Value;
int setCount = target.SetCount;
bool unioned = target.Union(left, right);
// Should be in the same set now
Assert.IsTrue(target.AreInSameSet(left, right));
// If unioned, the count decreased by 1
QuikGraphAssert.ImpliesIsTrue(unioned, () => setCount - 1 == target.SetCount);
}
}
private UndirectedGraph <string, TaggedEdge <string, double> > GetUndirectedFullGraph(int vert)
{
Console.WriteLine("Start");
var usedEdge = new List <KeyValuePair <int, int> >();
var random = new Random();
var graph = new UndirectedGraph <string, TaggedEdge <string, double> >();
var trueGraph = new UndirectedGraph <string, TaggedEdge <string, double> >();
var ds = new ForestDisjointSet <string>(vert);
for (int i = 0; i < vert; i++)
{
graph.AddVertex(i.ToString());
trueGraph.AddVertex(i.ToString());
ds.MakeSet(i.ToString());
}
for (int i = 0; i < vert; i++)
{
for (int j = i + 1; j < vert; j++)
{
graph.AddEdge(new TaggedEdge <string, double>(i.ToString(), j.ToString(), random.Next(100)));
}
}
return(graph);
}
private void OnVertexAdded([NotNull] TVertex vertex)
{
_sets.MakeSet(vertex);
}
protected override void InternalCompute()
{
var dic = new Dictionary <TVertex, HashSet <TEdge> >();
var cancelManager = this.Services.CancelManager;
var visetedVert = new HashSet <TVertex>();
var edges = new HashSet <TEdge>();
var queue = new BinaryQueue <TEdge, double>(this.edgeWeights);
var ds = new ForestDisjointSet <TVertex>(this.VisitedGraph.VertexCount);
foreach (var v in this.VisitedGraph.Vertices)
{
if (visetedVert.Count == 0)
{
visetedVert.Add(v);
}
ds.MakeSet(v);
dic.Add(v, new HashSet <TEdge>());
}
foreach (var e in this.VisitedGraph.Edges)
{
dic[e.Source].Add(e);
dic[e.Target].Add(e);
}
if (cancelManager.IsCancelling)
{
return;
}
var enumerator = visetedVert.GetEnumerator();
enumerator.MoveNext();
var lastVert = enumerator.Current;
foreach (var edge in dic[lastVert])
{
if (!edges.Contains(edge))
{
edges.Add(edge);
queue.Enqueue(edge);
}
}
if (cancelManager.IsCancelling)
{
return;
}
while (edges.Count > 0 && visetedVert.Count < VisitedGraph.VertexCount)
{
var mined = queue.Dequeue();
this.OnExamineEdge(mined);
if (!ds.AreInSameSet(mined.Source, mined.Target))
{
this.OnTreeEdge(mined);
ds.Union(mined.Source, mined.Target);
if (visetedVert.Contains(mined.Source))
{
lastVert = mined.Target;
visetedVert.Add(mined.Target);
}
else
{
lastVert = mined.Source;
visetedVert.Add(mined.Source);
}
foreach (var edge in dic[lastVert])
{
if (!edges.Contains(edge))
{
edges.Add(edge);
queue.Enqueue(edge);
}
}
}
}
}
protected override void InternalCompute()
{
var cancelManager = this.Services.CancelManager;
var visetedVert = new List <TVertex>();
var visetedEdges = new List <TEdge>();
var ds = new ForestDisjointSet <TVertex>(this.VisitedGraph.VertexCount);
foreach (var v in this.VisitedGraph.Vertices)
{
if (visetedVert.Count == 0)
{
visetedVert.Add(v);
}
ds.MakeSet(v);
}
if (cancelManager.IsCancelling)
{
return;
}
var queue = new BinaryQueue <TEdge, double>(this.edgeWeights);
foreach (var edge in this.VisitedGraph.Edges)
{
if (!visetedEdges.Contains(edge) && (visetedVert.Contains(edge.Source) || visetedVert.Contains(edge.Target)))
{
queue.Enqueue(edge);
visetedEdges.Add(edge);
}
}
if (cancelManager.IsCancelling)
{
return;
}
while (queue.Count > 0)
{
foreach (var edge in this.VisitedGraph.Edges)
{
if (!visetedEdges.Contains(edge) && (visetedVert.Contains(edge.Source) || visetedVert.Contains(edge.Target)))
{
queue.Enqueue(edge);
visetedEdges.Add(edge);
}
}
var e = queue.Dequeue();
this.OnExamineEdge(e);
if (!ds.AreInSameSet(e.Source, e.Target))
{
this.OnTreeEdge(e);
ds.Union(e.Source, e.Target);
if (visetedVert.Contains(e.Source))
{
visetedVert.Add(e.Target);
}
else
{
visetedVert.Add(e.Source);
}
}
}
}
private void OnVertexAdded(TVertex vertex)
{
_sets.MakeSet(vertex);
}
public void Union()
{
UnionTest(1, 2, 3, 4, 5);
UnionTest(
new TestVertex("1"),
new TestVertex("2"),
new TestVertex("3"),
new TestVertex("4"),
new TestVertex("5"));
UnionTest(
new EquatableTestVertex("1"),
new EquatableTestVertex("2"),
new EquatableTestVertex("3"),
new EquatableTestVertex("4"),
new EquatableTestVertex("5"));
#region Local function
void UnionTest <TValue>(
TValue value1,
TValue value2,
TValue value3,
TValue value4,
TValue value5)
{
ForestDisjointSet <TValue> set = MakeAndFillSet();
set.Union(value1, value2);
AssertSetSizes(set, 4, 5);
Assert.IsTrue(set.AreInSameSet(value1, value2));
set.Union(value4, value3);
AssertSetSizes(set, 3, 5);
Assert.IsTrue(set.AreInSameSet(value3, value4));
set.Union(value1, value4);
AssertSetSizes(set, 2, 5);
Assert.IsTrue(set.AreInSameSet(value1, value2));
Assert.IsTrue(set.AreInSameSet(value1, value3));
Assert.IsTrue(set.AreInSameSet(value1, value4));
set.Union(value1, value5);
AssertSetSizes(set, 1, 5);
Assert.IsTrue(set.AreInSameSet(value1, value2));
Assert.IsTrue(set.AreInSameSet(value1, value3));
Assert.IsTrue(set.AreInSameSet(value1, value4));
Assert.IsTrue(set.AreInSameSet(value1, value5));
// Already merged
set.Union(value1, value1);
AssertSetSizes(set, 1, 5);
Assert.IsTrue(set.AreInSameSet(value1, value2));
Assert.IsTrue(set.AreInSameSet(value1, value3));
Assert.IsTrue(set.AreInSameSet(value1, value4));
Assert.IsTrue(set.AreInSameSet(value1, value5));
set.Union(value1, value4);
AssertSetSizes(set, 1, 5);
Assert.IsTrue(set.AreInSameSet(value1, value2));
Assert.IsTrue(set.AreInSameSet(value1, value3));
Assert.IsTrue(set.AreInSameSet(value1, value4));
Assert.IsTrue(set.AreInSameSet(value1, value5));
set.Union(value4, value1);
AssertSetSizes(set, 1, 5);
Assert.IsTrue(set.AreInSameSet(value1, value2));
Assert.IsTrue(set.AreInSameSet(value1, value3));
Assert.IsTrue(set.AreInSameSet(value1, value4));
Assert.IsTrue(set.AreInSameSet(value1, value5));
set = MakeAndFillSet();
set.Union(value1, value2);
AssertSetSizes(set, 4, 5);
Assert.IsTrue(set.AreInSameSet(value1, value2));
set.Union(value2, value4);
AssertSetSizes(set, 3, 5);
Assert.IsTrue(set.AreInSameSet(value1, value2));
Assert.IsTrue(set.AreInSameSet(value1, value4));
set.Union(value5, value2);
AssertSetSizes(set, 2, 5);
Assert.IsTrue(set.AreInSameSet(value1, value2));
Assert.IsTrue(set.AreInSameSet(value1, value4));
Assert.IsTrue(set.AreInSameSet(value1, value5));
#region Local function
ForestDisjointSet <TValue> MakeAndFillSet()
{
var s = new ForestDisjointSet <TValue>();
s.MakeSet(value1);
s.MakeSet(value2);
s.MakeSet(value3);
s.MakeSet(value4);
s.MakeSet(value5);
AssertSetSizes(s, 5, 5);
return(s);
}
#endregion
}
#endregion
}