public ArrayList findShortWay(NodeClass fromThis, NodeClass toThis, GraphClass graph)
{
// Dijkstra's algorithm
// d - minimum weights of ways to other nodes
// u - marks of visited nodes
// p - parent of each node, its necessary for back way finding
d[graph.findNodeIndexByNodeNumber(fromThis.NodeNumber)] = 0;
for (int i = 0; i < sizeOfNodes; ++i)
{
// weights to every node is infinite from the start
int v = -1;
for (int j = 0; j < sizeOfNodes; ++j)
if (!u[j] && (v == -1 || d[j] < d[v]))
v = j;
if (d[v] == 999999999)
break;
u[v] = true;
for (int j = 0; j < graph.GraphNodes[v].nodeEdges.Count(); ++j)
{
// if current way have lower weight sum to the next node - set new weight and parent
int to = graph.findNodeIndexByNodeNumber(graph.GraphNodes[v].nodeEdges[j].NextNode.NodeNumber);
int len = graph.GraphNodes[v].nodeEdges[j].Weight;
if (d[v] + len < d[to])
{
d[to] = d[v] + len;
p[to] = v;
}
}
}
// find a way back from end to start and reverse it
ArrayList path = new ArrayList();
// i have no idea, how index v could be less than 0, but it has happened a few times
// programming is... magic!
for (int v = graph.findNodeIndexByNodeNumber(toThis.NodeNumber);
(v != graph.findNodeIndexByNodeNumber( fromThis.NodeNumber )) && (v >= 0) && (p[v] >= 0);
v = p[v])
path.Add(v);
path.Add(graph.findNodeIndexByNodeNumber( fromThis.NodeNumber ));
path.Reverse();
return path;
}
public EdgeClass(NodeClass cNextNode)
{
this.nextNode = cNextNode;
this.weight = 10000000;
}
public EdgeClass(NodeClass cNextNode, int cWeight)
{
this.nextNode = cNextNode;
this.weight = cWeight;
}
private void chooseTwoNodes(MouseEventArgs e)
{
//find which nodes was clicked
if (nodeClickedFirst == null)
{
nodeClickedFirst = graph.whichNodeWasClicked(new Point(e.X, e.Y));
if (nodeClickedFirst != null)
nodeClickedFirst.drawNode(paintBox, Color.Black, graph.NodeSelectedColor);
}
else
{
if (nodeClickedSecond == null)
{
nodeClickedSecond = graph.whichNodeWasClicked(new Point(e.X, e.Y));
if (nodeClickedSecond != null)
nodeClickedSecond.drawNode(paintBox, Color.Black, graph.NodeSelectedColor);
}
}
// if two nodes was clicked - do something
if (nodeClickedFirst != null && nodeClickedSecond != null)
{
switch (stateOfForm)
{
case stateEnum.stateEdgeAdding:
graph.addEdge(nodeClickedFirst, nodeClickedSecond);
break;
case stateEnum.stageShortWayFinding:
if (!graph.shortPathCalculation(nodeClickedFirst, nodeClickedSecond))
infoUpdate("PathNotExistS");
else
infoUpdate("InfoTextDefaultS");
break;
}
nodeClickedFirst = null;
nodeClickedSecond = null;
}
}
public void addEdge(NodeClass nextNode)
{
int weight = calculateWeight(nextNode);
EdgeClass newEdge = new EdgeClass(nextNode, weight);
nodeEdges.Add(newEdge);
}
private int calculateWeight(NodeClass nextNode)
{
// weight is a distance between nodes in px
int result = 0;
double x = Math.Pow(Convert.ToDouble(this.nodePosition.X - nextNode.nodePosition.X), 2);
double y = Math.Pow(Convert.ToDouble(this.nodePosition.Y - nextNode.nodePosition.Y), 2);
result = (int)Math.Floor(Math.Sqrt(x + y));
return result;
}