public DikstraProvider2(LightWeightGraph g, int v) : base(g.Nodes.Length)
{
int numNodes = g.Nodes.Length;
numberOfShortestPaths[v] = 1;
fromList = new List <int> [numNodes]; //List of nodes (we will use this to
//countPostcessors = new int[numNodes]; //This will hold a count of the number of shortestpaths stemming from
//we must set each node to infinite distance
for (int i = 0; i < numNodes; i++)
{
g.Nodes[i].NodeWeight = float.MaxValue;
fromList[i] = new List <int>(5);
}
//now we need to set our node to 0
g.Nodes[v].NodeWeight = 0.0f;
//now we need to setup our heap
ADT.IndexedItem[] items = new IndexedItem[numNodes];
for (int i = 0; i < numNodes; i++)
{
var n = g.Nodes[i];
items[i] = new IndexedItem(n.Id, n.NodeWeight);
}
MinHeapDikstra minHeap = new MinHeapDikstra(numNodes, items[v]);
//dikstra main
while (!minHeap.isEmpty())
{
var h = minHeap.extractMin();
int uIndex = h.NodeIndex;
this.S.Push(uIndex);
//check all edges
var u = g.Nodes[uIndex];
int uEdgeCount = g.Nodes[uIndex].Count;
for (int i = 0; i < uEdgeCount; i++)
{
float newWeight = h.NodeWeight + u.EdgeWeights[i];
int toIndex = u.Edge[i];
var to = items[toIndex];
float toNodeWeight = to.NodeWeight;
if (newWeight < toNodeWeight)
{
to.NodeWeight = newWeight;
fromList[toIndex].Clear();
fromList[toIndex].Add(uIndex);
numberOfShortestPaths[toIndex] = numberOfShortestPaths[uIndex];
if (to.HeapIndex == -1) //first encounter
{
minHeap.addItem(to);
}
else
{
minHeap.decreaseKey(to.HeapIndex);
}
}
else if (newWeight == toNodeWeight)
{
fromList[toIndex].Add(uIndex);//Add the node
numberOfShortestPaths[toIndex] += numberOfShortestPaths[uIndex];
}
}
}
}
public DikstraProvider2(LightWeightGraph g, int v) : base(g.Nodes.Length)
{
int numNodes = g.Nodes.Length;
numberOfShortestPaths[v] = 1;
fromList = new List <int> [numNodes]; //List of nodes (we will use this to
for (int i = 0; i < numNodes; i++)
{
fromList[i] = new List <int>();
}
//now we need to setup our heap
//set each node to infinite distance
ADT.IndexedItem[] items = new IndexedItem[numNodes];
for (int i = 0; i < numNodes; i++)
{
items[i] = new IndexedItem(i, double.MaxValue);
}
items[v].NodeWeight = 0;
MinHeapDikstra minHeap = new MinHeapDikstra(numNodes, items[v]);
//dikstra main
while (!minHeap.isEmpty())
{
var h = minHeap.extractMin();
int uIndex = h.NodeIndex;
S.Push(uIndex);
//check all edges
var u = g.Nodes[uIndex];
int uEdgeCount = g.Nodes[uIndex].Count;
for (int i = 0; i < uEdgeCount; i++)
{
double newWeight = h.NodeWeight + u.EdgeWeights[i];
int toIndex = u.Edge[i];
var to = items[toIndex];
double toNodeWeight = to.NodeWeight;
if (newWeight < toNodeWeight)
{
to.NodeWeight = newWeight;
fromList[toIndex].Clear();
fromList[toIndex].Add(uIndex);
numberOfShortestPaths[toIndex] = numberOfShortestPaths[uIndex];
if (to.HeapIndex == -1) //first encounter
{
minHeap.addItem(to);
}
else
{
minHeap.decreaseKey(to.HeapIndex);
}
}
else if (newWeight == toNodeWeight)
{
fromList[toIndex].Add(uIndex);//Add the node
numberOfShortestPaths[toIndex] += numberOfShortestPaths[uIndex];
}
}
}
}
