public static bool HasPath(Graphs.Node <T> source, Graphs.Node <T> destination)
{
var nextToVisit = new Queue <Graphs.Node <T> >();
nextToVisit.Push(source);
while (nextToVisit.Size > 0)
{
var node = nextToVisit.Pop();
if (node == destination)
{
return(true);
}
if (node.IsVisited)
{
continue;
}
node.IsVisited = true;
var current = node.Adjacent.Head;
while (current != null)
{
var edge = current.Value;
nextToVisit.Push(edge.Destination);
current = current.Next;
}
}
return(false);
}
private void Form1_Load(object sender, EventArgs e)
{
nodeA = new Graphs.Node("A");
nodeB = new Graphs.Node("B");
nodeC = new Graphs.Node("C");
nodeD = new Graphs.Node("D");
nodeE = new Graphs.Node("E");
nodeF = new Graphs.Node("F");
nodeG = new Graphs.Node("G");
nodeH = new Graphs.Node("H");
nodeI = new Graphs.Node("I");
nodeX = new Graphs.Node("X");
nodeA.Neighbours.Add(nodeB);
nodeA.Neighbours.Add(nodeC);
nodeB.Neighbours.Add(nodeA);
nodeB.Neighbours.Add(nodeD);
nodeB.Neighbours.Add(nodeE);
nodeC.Neighbours.Add(nodeA);
nodeC.Neighbours.Add(nodeF);
nodeC.Neighbours.Add(nodeG);
nodeD.Neighbours.Add(nodeB);
nodeD.Neighbours.Add(nodeE);
nodeE.Neighbours.Add(nodeB);
nodeE.Neighbours.Add(nodeD);
nodeF.Neighbours.Add(nodeC);
nodeF.Neighbours.Add(nodeG);
nodeG.Neighbours.Add(nodeC);
nodeG.Neighbours.Add(nodeF);
nodeG.Neighbours.Add(nodeH);
nodeG.Neighbours.Add(nodeI);
nodeH.Neighbours.Add(nodeG);
nodeH.Neighbours.Add(nodeI);
nodeI.Neighbours.Add(nodeG);
nodeI.Neighbours.Add(nodeH);
nodeI.Neighbours.Add(nodeX);
nodeX.Neighbours.Add(nodeI);
}
public static void Run(Graphs.Node <T> start)
{
start.DistanceFromSource = 0;
start.IsVisited = true;
var queue = new Queue <Edge <T> >();
var current = start.Adjacent.Head;
while (current != null)
{
var edge = current.Value;
queue.Push(edge);
current = current.Next;
}
while (queue.Size > 0)
{
var currentEdge = queue.Pop();
var currentNode = currentEdge.Source;
var destinationNode = currentEdge.Destination;
var adjNode = destinationNode.Adjacent.Head;
while (adjNode != null)
{
var edge = adjNode.Value;
if (!edge.Destination.IsVisited)
{
queue.Push(edge);
}
adjNode = adjNode.Next;
}
if (currentNode.DistanceFromSource + currentEdge.Weight < destinationNode.DistanceFromSource)
{
destinationNode.DistanceFromSource = currentNode.DistanceFromSource + currentEdge.Weight;
destinationNode.PreviousNode = currentNode;
}
currentNode.IsVisited = true;
}
}
private void depthBtn_Click(object sender, EventArgs e)
{
ArrayList allVisitedNodes = new ArrayList();
Stack <Graphs.Node> nodeStack = new Stack <Graphs.Node>();
bool end = false;
Graphs.Node currentNode = nodeA;
allVisitedNodes.Add(currentNode);
while (!end)
{
Graphs.Node nextNode = currentNode.GetNextUnvisited((Graphs.Node[])allVisitedNodes.ToArray(typeof(Graphs.Node)));
if (nextNode != null)
{
nodeStack.Push(currentNode);
currentNode = nextNode;
allVisitedNodes.Add(currentNode);
}
else
{
if (currentNode == nodeA)
{
end = true;
}
else
{
currentNode = nodeStack.Pop();
}
}
}
foreach (Graphs.Node node in allVisitedNodes)
{
nodeBox.Text += node.Name;
}
}
private void breadthBtn_Click(object sender, EventArgs e)
{
ArrayList allVisitedNodes = new ArrayList();
Queue <Graphs.Node> nodeQueue = new Queue <Graphs.Node>();
bool end = false;
Graphs.Node currentNode = nodeA;
allVisitedNodes.Add(currentNode);
while (!end)
{
ArrayList unvisitedNodes = new ArrayList();
unvisitedNodes.AddRange(currentNode.GetUnvisitedNeighbours((Graphs.Node[])allVisitedNodes.ToArray(typeof(Graphs.Node))));
foreach (Graphs.Node node in unvisitedNodes)
{
nodeQueue.Enqueue(node);
}
if (nodeQueue.Count > 0)
{
allVisitedNodes.Add(currentNode);
currentNode = nodeQueue.Dequeue();
}
else
{
end = true;
}
}
foreach (Graphs.Node node in allVisitedNodes)
{
nodeBox.Text += node.Name;
}
}
