private PrimMSTAlgorithm(EdgeWeightedGraph graph)
{
this._edgeTo = new Edge[graph.VerticesCount];
this._distTo = new Double[graph.VerticesCount];
this._visited = new Boolean[graph.VerticesCount];
this._crossingEdgesByWeight = new IndexedMinPQ <Double>(graph.VerticesCount);
for (int i = 0; i < graph.VerticesCount; i++)
{
this._distTo[i] = Double.PositiveInfinity;
}
for (int i = 0; i < graph.VerticesCount; i++)
{
if (!this._visited[i])
{
this.Prim(graph, i);
}
}
this._lazyWeight = new Lazy <Double>(() =>
{
Double weight = 0;
foreach (Edge edge in this.GetEdges())
{
weight += edge.Weight;
}
return(weight);
});
}
public void Test_Empty_OnCreation()
{
IndexedMinPQ <Int32> pq = new IndexedMinPQ <Int32>(1);
Assert.True(pq.IsEmpty);
Assert.Equal(0, pq.Count);
}
HashSet <int> _processed; //All Processed nodes.
public Dijkstra(List <SharedClasses.IEdgeWithWeight> edges, int source)
{
_edges = edges;
_source = source;
_pQ = new IndexedMinPQ();
_adj = Helper.BuildAdjListWithWeights(_edges);
_parents = new Dictionary <int, int>();
_currMinDistances = new Dictionary <int, int>();
_processed = new HashSet <int>();
}
public void Test_ItemAt()
{
IndexedMinPQ <Int32> pq = new IndexedMinPQ <Int32>(10);
for (int i = 1; i < 11; i++)
{
pq.Add(i, i);
}
Assert.Equal(2, pq.ItemAt(2));
}
public void Test_Add_MinIndex()
{
IndexedMinPQ <Int32> pq = new IndexedMinPQ <Int32>(10);
for (int i = 1; i < 11; i++)
{
pq.Add(i, i);
}
Assert.Equal(1, pq.MinIndex());
}
public void Test_NotEmpty_WhenAdding()
{
IndexedMinPQ <Int32> pq = new IndexedMinPQ <Int32>(2)
{
{ 0, 18 },
{ 1, 2 }
};
Assert.False(pq.IsEmpty);
Assert.Equal(2, pq.Count);
}
public void Test_Contains()
{
IndexedMinPQ <Int32> pq = new IndexedMinPQ <Int32>(5);
for (int i = 1; i < 6; i++)
{
pq.Add(i, i);
}
Assert.True(pq.Contains(4));
}
public void Test_Empty_WhenCleaning()
{
IndexedMinPQ <Int32> pq = new IndexedMinPQ <Int32>(1)
{
{ 0, 2 }
};
pq.DeleteMin();
Assert.True(pq.IsEmpty);
Assert.Equal(0, pq.Count);
}
public void Test_DecreaseItem()
{
IndexedMinPQ <Int32> pq = new IndexedMinPQ <Int32>(5);
for (int i = 1; i < 6; i++)
{
pq.Add(i, i);
}
pq.DecreaseItem(1, -1);
Assert.Equal(-1, pq.ItemAt(1));
}
public void Test_Delete()
{
IndexedMinPQ <Int32> pq = new IndexedMinPQ <Int32>(5);
for (int i = 1; i < 6; i++)
{
pq.Add(i, i);
}
pq.Delete(4);
Assert.False(pq.Contains(4));
}
public void Test_AddDeleteMin_Order()
{
IndexedMinPQ <Int32> pq = new IndexedMinPQ <Int32>(10);
for (int i = 1; i < 11; i++)
{
pq.Add(i, i);
}
for (int i = 1; i < 11; i++)
{
Assert.Equal(i, pq.DeleteMin());
}
}
public DijkstraShortestPathAlgorithm(EdgeWeightedDigraph graph, Int32 vertice)
{
foreach (Edge edge in graph.GetEdges())
{
if (edge.Weight < 0)
{
throw new InvalidOperationException("Edge" + edge + " has negative weight.");
}
}
this._distTo = new Double[graph.VerticesCount];
this._edgeTo = new Edge[graph.VerticesCount];
for (int i = 0; i < graph.VerticesCount; i++)
{
this._distTo[i] = Double.PositiveInfinity;
}
this._distTo[vertice] = 0.0;
// Relax vertices in order of distance from vertice.
this._crossingEdgesByWeight = new IndexedMinPQ <Double>(graph.VerticesCount)
{
{ vertice, this._distTo[vertice] }
};
while (!this._crossingEdgesByWeight.IsEmpty)
{
Int32 v = this._crossingEdgesByWeight.DeleteMin();
foreach (Edge edge in graph.GetAdjacentVertices(v))
{
this.Relax(edge);
}
}
}
