public Path GetShortestPath(int startVertexIndex, int endVertexIndex)
{
if (startVertexIndex == endVertexIndex)
{
throw new ArgumentException("Start Vertex should be different from End Vertex");
}
DeclareArrays();
Queue <int> queue = new Queue <int>();
queue.Enqueue(startVertexIndex);
Visited[startVertexIndex] = true;
VisitedVertices.Add(Graph.Vertices[startVertexIndex]);
bool foundEnd = false;
while (queue.Count != 0 && !foundEnd)
{
int vertex = queue.Dequeue();
for (var i = 0; i < Graph.AdjacencyList.Vertices[vertex].Count; i++)
{
int neighbor = Graph.AdjacencyList.Vertices[vertex][i];
int neighborEdge = Graph.AdjacencyList.Edges[vertex][i];
if (Visited[neighbor])
{
continue;
}
queue.Enqueue(neighbor);
Visited[neighbor] = true;
VisitedVertices.Add(Graph.Vertices[neighbor]);
PreviousArray[neighbor] = vertex;
PreviousEdgeArray[neighbor] = neighborEdge;
if (neighbor == endVertexIndex)
{
foundEnd = true;
break;
}
}
}
if (foundEnd)
{
Path shortestPath = new Path(startVertexIndex, endVertexIndex, Graph, PreviousArray, PreviousEdgeArray);
return(shortestPath);
}
throw new ArgumentException("Couldn't find a correct path between those vertices");
}
public void Search(int startVertexIndex)
{
DeclareArrays();
Weights[startVertexIndex] = 0;
List <DijkstraVertex> dijkstraVertices = new List <DijkstraVertex> {
new DijkstraVertex(startVertexIndex, 0)
};
while (dijkstraVertices.Count != 0)
{
dijkstraVertices = dijkstraVertices.OrderBy(x => x.Weight).ToList();
int currentVertexIndex = dijkstraVertices[0].Index;
dijkstraVertices.RemoveAt(0);
for (int i = 0; i < Graph.AdjacencyList.Vertices[currentVertexIndex].Count; i++)
{
int neighborIndex = Graph.AdjacencyList.Vertices[currentVertexIndex][i];
if (Visited[neighborIndex])
{
continue;
}
int edgeToNeighbor = Graph.AdjacencyList.Edges[currentVertexIndex][i];
double weightToNeighbor = Graph.EdgesWeights[edgeToNeighbor];
if (Weights[neighborIndex] > Weights[currentVertexIndex] + weightToNeighbor)
{
Weights[neighborIndex] = Weights[currentVertexIndex] + weightToNeighbor;
PreviousArray[neighborIndex] = currentVertexIndex;
DijkstraVertex newDijkstraVertex = new DijkstraVertex(neighborIndex, Weights[neighborIndex]);
if (!dijkstraVertices.Contains(newDijkstraVertex))
{
dijkstraVertices.Add(newDijkstraVertex);
}
else
{
DijkstraVertex oldDijkstraVertex = dijkstraVertices.First(p => p.Index == neighborIndex);
oldDijkstraVertex.Weight = Weights[neighborIndex];
}
}
}
Visited[currentVertexIndex] = true;
VisitedVertices.Add(Graph.Vertices[currentVertexIndex]);
}
}
private void MainLoopForSeparatedConnectedGraph(Queue <int> queue, bool[] visited, int[] previous, int startVertex)
{
queue.Enqueue(startVertex);
visited[startVertex] = true;
VisitedVertices.Add(Graph.Vertices[startVertex]);
while (queue.Count != 0)
{
int vertex = queue.Dequeue();
foreach (int neighbor in Graph.AdjacencyList.Vertices[vertex])
{
if (visited[neighbor])
{
continue;
}
queue.Enqueue(neighbor);
visited[neighbor] = true;
VisitedVertices.Add(Graph.Vertices[neighbor]);
previous[neighbor] = vertex;
}
}
}
public Path GetShortestPath(int startVertexIndex, int endVertexIndex)
{
if (startVertexIndex == endVertexIndex)
{
throw new ArgumentException("Start Vertex should be different from End Vertex");
}
DeclareArrays();
Weights[startVertexIndex] = 0;
double absoluteDistanceToEnd = Graph.Vertices[startVertexIndex].DistanceTo(Graph.Vertices[endVertexIndex]);
List <AStarVertex> aStarVertices = new List <AStarVertex> {
new AStarVertex(startVertexIndex, 0, absoluteDistanceToEnd)
};
bool foundEnd = false;
while (aStarVertices.Count != 0 && !foundEnd)
{
aStarVertices = aStarVertices.OrderBy(x => x.Weight + x.StraightLineDistanceToEnd).ToList();
int currentVertexIndex = aStarVertices[0].Index;
aStarVertices.RemoveAt(0);
for (int i = 0; i < Graph.AdjacencyList.Vertices[currentVertexIndex].Count; i++)
{
int neighborIndex = Graph.AdjacencyList.Vertices[currentVertexIndex][i];
if (Visited[neighborIndex])
{
continue;
}
int edgeToNeighbor = Graph.AdjacencyList.Edges[currentVertexIndex][i];
double weightToNeighbor = Graph.EdgesWeights[edgeToNeighbor];
absoluteDistanceToEnd = Graph.Vertices[neighborIndex].DistanceTo(Graph.Vertices[endVertexIndex]);
if (Weights[neighborIndex] > Weights[currentVertexIndex] + weightToNeighbor)
{
Weights[neighborIndex] = Weights[currentVertexIndex] + weightToNeighbor;
PreviousArray[neighborIndex] = currentVertexIndex;
PreviousEdgeArray[neighborIndex] = edgeToNeighbor;
AStarVertex newAStarVertex =
new AStarVertex(neighborIndex, Weights[neighborIndex], absoluteDistanceToEnd);
if (!aStarVertices.Contains(newAStarVertex))
{
aStarVertices.Add(newAStarVertex);
}
else
{
AStarVertex oldAStarVertex = aStarVertices.First(p => p.Index == neighborIndex);
oldAStarVertex.Weight = Weights[neighborIndex];
}
}
}
Visited[currentVertexIndex] = true;
VisitedVertices.Add(Graph.Vertices[currentVertexIndex]);
if (currentVertexIndex == endVertexIndex)
{
foundEnd = true;
}
}
if (foundEnd)
{
Path shortestPath = new Path(startVertexIndex, endVertexIndex, Graph, PreviousArray, PreviousEdgeArray);
return(shortestPath);
}
throw new ArgumentException("Couldn't find a correct path between those vertices");
}