// Find a shortest path between the two nodes
// by using a label correcting algorithm.
// Return the path's total cost.
public int FindLabelCorrectingPath(NetworkNode fromNode, NetworkNode toNode,
out List <NetworkNode> pathNodes, out List <NetworkLink> pathLinks)
{
// Build a shortest path tree.
FindLabelCorrectingPathTree(fromNode);
// Follow the tree's links back from toNode to fromNode.
return(FindSpanningTreePath(fromNode, toNode, out pathNodes, out pathLinks));
}
// Find any path between the two nodes. Return the path's total cost.
public int FindAnyPath(NetworkNode fromNode, NetworkNode toNode,
out List <NetworkNode> pathNodes, out List <NetworkLink> pathLinks)
{
// Make a spanning tree.
bool isConnected;
MakeSpanningTree(fromNode, out isConnected);
// Follow the tree's links back from toNode to fromNode.
return(FindSpanningTreePath(fromNode, toNode, out pathNodes, out pathLinks));
}
// Return true if a neighbor has the indicated color.
public bool NeighborHasColor(Color color)
{
foreach (NetworkLink link in Links)
{
NetworkNode neighbor = link.Nodes[1];
if (neighbor.IsColored && (neighbor.BackColor == color))
{
return(true);
}
}
return(false);
}
// Make a link between the two nodes.
public NetworkLink(NetworkNode node0, NetworkNode node1)
{
Nodes[0] = node0;
Nodes[1] = node1;
float dx = node0.Location.X - node1.Location.X;
float dy = node0.Location.Y - node1.Location.Y;
Cost = (int)Math.Sqrt(dx * dx + dy * dy);
Capacity = Rand.Next(1, 3) + Rand.Next(0, 3);
node0.Links.Add(this);
}
// Craete a network from a network file.
public static Network LoadNetwork(string filename)
{
// Make a new network.
Network network = new Network();
// Read the data.
string[] allLines = File.ReadAllLines(filename);
// Get the number of nodes.
int numNodes = int.Parse(allLines[0]);
// Create the nodes.
for (int i = 0; i < numNodes; i++)
{
network.AllNodes.Add(new NetworkNode());
network.AllNodes[i].Index = i;
}
// Read the nodes.
char[] separators = { ',' };
for (int i = 1; i < allLines.Length; i++)
{
NetworkNode node = network.AllNodes[i - 1];
string[] nodeFields = allLines[i].Split(separators);
// Get the node's text and coordinates.
node.Name = nodeFields[0];
node.Location = new PointF(
int.Parse(nodeFields[1]),
int.Parse(nodeFields[2])
);
// Get the node's links.
for (int j = 3; j < nodeFields.Length; j += 3)
{
// Get the next link.
NetworkLink link = new NetworkLink();
link.Nodes[0] = node;
int index = int.Parse(nodeFields[j]);
link.Nodes[1] = network.AllNodes[index];
link.Cost = int.Parse(nodeFields[j + 1]);
link.Capacity = int.Parse(nodeFields[j + 2]);
node.Links.Add(link);
}
}
return(network);
}
private void allPairsToolStripButton_Click(object sender, EventArgs e)
{
// Find all pairs shortest paths.
int[,] distance;
int[,] via;
TheNetwork.FindAllPairsPaths(out distance, out via);
// Display the arrays.
Console.WriteLine("Final arrays:");
Console.WriteLine("distance:");
Console.WriteLine(ArrayToString(distance, false));
Console.WriteLine("via:");
Console.WriteLine(ArrayToString(via, true));
// Display all of the paths.
int N = TheNetwork.AllNodes.Count;
for (int i = 0; i < N; i++)
{
for (int j = 0; j < N; j++)
{
List <NetworkNode> path =
TheNetwork.FindAllPairsPath(distance, via, i, j);
NetworkNode startNode = TheNetwork.AllNodes[i];
NetworkNode endNode = TheNetwork.AllNodes[j];
Console.Write(startNode.Name + " --> " + endNode.Name +
" [" + distance[i, j] + "] : ");
if (path == null)
{
Console.WriteLine("No path");
}
else
{
foreach (NetworkNode viaNode in path)
{
Console.Write(viaNode.Name + " ");
}
Console.WriteLine("");
}
}
}
Console.WriteLine("");
MessageBox.Show("See the Output Window for results.");
}
// Add a link to the indicated node.
public void AddLinkTo(NetworkNode node)
{
new NetworkLink(this, node);
}
// Find a shortest path tree rooted at fromNode
// by using a label correcting algorithm.
// Return the tree's total cost.
public int FindLabelCorrectingPathTree(NetworkNode fromNode)
{
// Reset the network.
ResetNetwork();
// Set all nodes' distances to infinity and their labels to 0.
foreach (NetworkNode node in AllNodes)
{
node.Distance = int.MaxValue;
node.Text = "0";
}
// Add the start node to the shortest path tree.
fromNode.Visited = true;
fromNode.Distance = 0;
// Make the candidate list.
Queue <NetworkLink> candidateLinks = new Queue <NetworkLink>();
// Add the start node's links to the candidate list.
foreach (NetworkLink link in fromNode.Links)
{
candidateLinks.Enqueue(link);
}
// Make a shortest path tree.
while (candidateLinks.Count > 0)
{
// Use the first link in the candidate list.
NetworkLink link = candidateLinks.Dequeue();
// See if link this improves its destination node's distance.
int newDistance = link.Nodes[0].Distance + link.Cost;
NetworkNode toNode = link.Nodes[1];
if (newDistance < toNode.Distance)
{
// This is an improvement.
// Update the node's distance.
toNode.Distance = newDistance;
// Update the node's FromNode and FromLink.
toNode.FromNode = link.Nodes[0];
toNode.FromLink = link;
// Update the node's label.
int numUpdates = int.Parse(toNode.Text);
numUpdates++;
toNode.Text = numUpdates.ToString();
// Add the node's links to the candidate list.
foreach (NetworkLink newLink in toNode.Links)
{
candidateLinks.Enqueue(newLink);
}
}
}
// Set the Visited properties for the visited nodes and links.
int cost = 0;
foreach (NetworkNode node in AllNodes)
{
node.Visited = true;
if (node.FromLink != null)
{
node.FromLink.Visited = true;
cost += node.FromLink.Cost;
}
}
// Return the total cost.
return(cost);
}
// Follow a spanning tree's links to find a path from fromNode to toNode.
public int FindSpanningTreePath(NetworkNode fromNode, NetworkNode toNode,
out List <NetworkNode> pathNodes, out List <NetworkLink> pathLinks)
{
// Follow the tree's links back from toNode to fromNode.
pathNodes = new List <NetworkNode>();
pathLinks = new List <NetworkLink>();
NetworkNode currentNode = toNode;
while (currentNode != fromNode)
{
// Add this node to the path.
pathNodes.Add(currentNode);
// Find the previous node.
NetworkNode prevNode = currentNode.FromNode;
// Find the link that leads to currentNode.
NetworkLink prevLink = null;
foreach (NetworkLink link in prevNode.Links)
{
if (link.Nodes[1] == currentNode)
{
prevLink = link;
break;
}
}
// Make sure we found the link.
Debug.Assert(prevLink != null);
// Add the link to the path.
pathLinks.Add(prevLink);
// Move to the next node.
currentNode = prevNode;
} // while (currentNode != fromNode)
// Add the start node.
pathNodes.Add(fromNode);
// Reverse the order of the nodes and links.
pathNodes.Reverse();
pathLinks.Reverse();
// Unmark all nodes and links.
DeselectNodes();
DeselectBranches();
// Marks the path's nodes and links.
foreach (NetworkNode node in pathNodes)
{
node.Visited = true;
}
foreach (NetworkLink link in pathLinks)
{
link.Visited = true;
}
// Calculate the cost of the path.
int cost = 0;
foreach (NetworkLink link in pathLinks)
{
cost += link.Cost;
}
// Return the cost.
return(cost);
}
// Find a shortest path tree rooted at fromNode
// by using a label setting algorithm.
// Return the tree's total cost.
public int FindLabelSettingPathTree(NetworkNode fromNode)
{
// Reset the network.
ResetNetwork();
// Keep track of the number of nodes in the tree.
int numDone = 0;
// Add the start node to the shortest path tree.
fromNode.Visited = true;
fromNode.Distance = 0;
fromNode.Text = numDone.ToString();
numDone++;
// Track the tree's total cost.
int cost = 0;
// Make the candidate list.
List <NetworkLink> candidateLinks = new List <NetworkLink>();
// Add the start node's links to the candidate list.
foreach (NetworkLink link in fromNode.Links)
{
candidateLinks.Add(link);
}
// Make a shortest path tree.
while (candidateLinks.Count > 0)
{
// Find the best link.
NetworkLink bestLink = null;
int bestCost = int.MaxValue;
for (int i = candidateLinks.Count - 1; i >= 0; i--)
{
NetworkLink testLink = candidateLinks[i];
// See if the link leads outside the tree.
if (testLink.Nodes[1].Visited)
{
// Remove this link.
candidateLinks.RemoveAt(i);
}
else
{
// See if this link is an improvement.
int testCost = testLink.Nodes[0].Distance + testLink.Cost;
if (testCost < bestCost)
{
bestCost = testCost;
bestLink = testLink;
}
}
}
// If we found no link, then the candidate
// list must be empty and we're done.
if (bestLink == null)
{
Debug.Assert(candidateLinks.Count == 0);
break;
}
// Use this link.
// Remove it from the candidate list.
candidateLinks.Remove(bestLink);
// Add the node to the tree.
NetworkNode bestNode = bestLink.Nodes[1];
bestNode.Distance = bestLink.Nodes[0].Distance + bestLink.Cost;
bestNode.Visited = true;
bestLink.Visited = true;
bestNode.FromNode = bestLink.Nodes[0];
bestNode.Text = numDone.ToString();
numDone++;
// Add the node's links to the tree.
foreach (NetworkLink newLink in bestNode.Links)
{
if (!newLink.Nodes[1].Visited)
{
candidateLinks.Add(newLink);
}
}
// Add the link's cost to the tree's total cost.
cost += bestLink.Cost;
}
// Return the total cost.
return(cost);
}
// Build a minimal spanning tree. Return its total cost.
// When it adds a node to the spanning tree, the algorithm
// also adds its links that lead outside of the tree to a list.
// Later it searches that list for a minimal link.
public int MakeMinimalSpanningTree(NetworkNode root, out bool isConnected)
{
// Reset the network.
ResetNetwork();
// The total cost of the links in the spanning tree.
int totalCost = 0;
// Add the root node's links to the link candidate list.
List <NetworkLink> candidateLinks = new List <NetworkLink>();
foreach (NetworkLink link in root.Links)
{
candidateLinks.Add(link);
}
// Visit the root node.
root.Visited = true;
// Process the list until it's empty.
while (candidateLinks.Count > 0)
{
// Find the link with the lowest cost.
NetworkLink bestLink = candidateLinks[0];
int bestCost = bestLink.Cost;
for (int i = 1; i < candidateLinks.Count; i++)
{
if (candidateLinks[i].Cost < bestCost)
{
// Save this improvement.
bestLink = candidateLinks[i];
bestCost = bestLink.Cost;
}
}
// Remove the link from the list.
candidateLinks.Remove(bestLink);
// Get the node at the other end of the link.
NetworkNode toNode = bestLink.Nodes[1];
// See if the link's node is still unmarked.
if (!toNode.Visited)
{
// Use the link.
bestLink.Visited = true;
totalCost += bestLink.Cost;
toNode.Visited = true;
// Record the node that got us here.
toNode.FromNode = bestLink.Nodes[0];
// Process toNode's links.
foreach (NetworkLink newLink in toNode.Links)
{
// If the node hasn't been visited,
// add the link to the list.
if (!newLink.Nodes[1].Visited)
{
candidateLinks.Add(newLink);
}
}
}
}
// See if the network is connected.
isConnected = true;
foreach (NetworkNode node in AllNodes)
{
if (!node.Visited)
{
isConnected = false;
break;
}
}
return(totalCost);
}
// Build a spanning tree. Return its total cost.
public int MakeSpanningTree(NetworkNode root, out bool isConnected)
{
// Reset the network.
ResetNetwork();
// The total cost of the links in the spanning tree.
int totalCost = 0;
// Push the root node onto the stack.
Stack <NetworkNode> stack = new Stack <NetworkNode>();
stack.Push(root);
// Visit the root node.
root.Visited = true;
// Process the stack until it's empty.
while (stack.Count > 0)
{
// Get the next node from the stack.
NetworkNode node = stack.Pop();
// Process the node's links.
foreach (NetworkLink link in node.Links)
{
// Only use the link if the destination
// node hasn't been visited.
NetworkNode toNode = link.Nodes[1];
if (!toNode.Visited)
{
// Mark the node as visited.
toNode.Visited = true;
// Record the node that got us here.
toNode.FromNode = node;
// Mark the link as part of the tree.
link.Visited = true;
// Push the node onto the stack.
stack.Push(toNode);
// Add the link's cost to the total cost.
totalCost += link.Cost;
}
}
}
// See if the network is connected.
isConnected = true;
foreach (NetworkNode node in AllNodes)
{
if (!node.Visited)
{
isConnected = false;
break;
}
}
return(totalCost);
}
// Return the network's connected components.
public List <List <NetworkNode> > GetConnectedComponents()
{
// Reset the network.
ResetNetwork();
// Keep track of the number of nodes visited.
int numVisited = 0;
// Make the result list of lists.
List <List <NetworkNode> > components = new List <List <NetworkNode> >();
// Repeat until all nodes are in a connected component.
while (numVisited < AllNodes.Count)
{
// Find a node that hasn't been visited.
NetworkNode startNode = null;
foreach (NetworkNode node in AllNodes)
{
if (!node.Visited)
{
startNode = node;
break;
}
}
// Make sure we found one.
Debug.Assert(startNode != null);
// Add the start node to the stack.
Stack <NetworkNode> stack = new Stack <NetworkNode>();
stack.Push(startNode);
startNode.Visited = true;
numVisited++;
// Add the node to a new connected component.
List <NetworkNode> component = new List <NetworkNode>();
components.Add(component);
component.Add(startNode);
// Process the stack until it's empty.
while (stack.Count > 0)
{
// Get the next node from the stack.
NetworkNode node = stack.Pop();
// Process the node's links.
foreach (NetworkLink link in node.Links)
{
// Only use the link if the destination
// node hasn't been visited.
NetworkNode toNode = link.Nodes[1];
if (!toNode.Visited)
{
// Mark the node as visited.
toNode.Visited = true;
// Mark the link as part of the tree.
link.Visited = true;
numVisited++;
// Add the node to the current connected component.
component.Add(toNode);
// Push the node onto the stack.
stack.Push(toNode);
}
}
}
}
// Return the components.
return(components);
}
// Traverse the network in breadth-first order.
public List <NetworkNode> BreadthFirstTraverse(NetworkNode startNode, out bool isConnected)
{
// Reset the network.
ResetNetwork();
// Keep track of the number of nodes in the traversal.
int numDone = 0;
// Add the start node to the queue.
Queue <NetworkNode> queue = new Queue <NetworkNode>();
queue.Enqueue(startNode);
// Visit the start node.
List <NetworkNode> traversal = new List <NetworkNode>();
traversal.Add(startNode);
startNode.Visited = true;
startNode.Text = numDone.ToString();
numDone++;
// Process the queue until it's empty.
while (queue.Count > 0)
{
// Get the next node from the queue.
NetworkNode node = queue.Dequeue();
// Process the node's links.
foreach (NetworkLink link in node.Links)
{
NetworkNode toNode = link.Nodes[1];
// Only use the link if the destination
// node hasn't been visited.
if (!toNode.Visited)
{
// Mark the node as visited.
toNode.Visited = true;
toNode.Text = numDone.ToString();
numDone++;
// Add the node to the traversal.
traversal.Add(toNode);
// Add the link to the traversal.
link.Visited = true;
// Add the node onto the queue.
queue.Enqueue(toNode);
}
}
}
// See if the network is connected.
isConnected = true;
foreach (NetworkNode node in AllNodes)
{
if (!node.Visited)
{
isConnected = false;
break;
}
}
return(traversal);
}
// Make links from node0 to node1 and node1 to node0.
public void MakeLinks(NetworkNode node0, NetworkNode node1)
{
new NetworkLink(node0, node1);
new NetworkLink(node1, node0);
}
// Add a node or link if appropriate.
private void networkPictureBox_MouseClick(object sender, MouseEventArgs e)
{
if (Mode == Modes.AddNode)
{
// Add a node.
NetworkNode node = new NetworkNode();
node.Location = e.Location;
node.Index = TheNetwork.AllNodes.Count;
node.Name = NumberToLetters(node.Index);
TheNetwork.AllNodes.Add(node);
networkPictureBox.Refresh();
}
else if (
(Mode == Modes.AddLink1) ||
(Mode == Modes.AddLink2))
{
// Add a link.
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
if (e.Button == MouseButtons.Left)
{
Node0 = node;
}
else
{
Node1 = node;
}
// See if we have both nodes.
if ((Node0 != null) && (Node1 != null))
{
// Make the link.
if (Mode == Modes.AddLink1)
{
TheNetwork.MakeLink(Node0, Node1);
}
else
{
TheNetwork.MakeLinks(Node0, Node1);
}
// We're done with this link.
Node0 = null;
Node1 = null;
// Redraw.
networkPictureBox.Refresh();
}
}
}
else if (Mode == Modes.DFTraversal)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
// Traverse the network.
bool isConnected;
List <NetworkNode> traversal =
TheNetwork.DepthFirstTraverse(node, out isConnected);
// Display the traversal.
string txt = "";
foreach (NetworkNode traversalNode in traversal)
{
txt += " " + traversalNode.ToString();
}
toolStripStatusLabel1.Text = "Traversal: " + txt;
if (isConnected)
{
txt += " Connected.";
}
else
{
txt += " Not connected.";
}
toolStripStatusLabel1.Text = txt;
Console.WriteLine(txt);
// Redraw the network.
networkPictureBox.Refresh();
}
}
else if (Mode == Modes.BFTraversal)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
// Traverse the network.
bool isConnected;
List <NetworkNode> traversal =
TheNetwork.BreadthFirstTraverse(node, out isConnected);
// Display the traversal.
string txt = "";
foreach (NetworkNode traversalNode in traversal)
{
txt += " " + traversalNode.ToString();
}
toolStripStatusLabel1.Text = "Traversal: " + txt;
if (isConnected)
{
txt += " Connected.";
}
else
{
txt += " Not connected.";
}
toolStripStatusLabel1.Text = txt;
Console.WriteLine(txt);
// Redraw the network.
networkPictureBox.Refresh();
}
}
else if (Mode == Modes.SpanningTree)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
// Build a spanning tree.
bool isConnected;
float cost = TheNetwork.MakeSpanningTree(node, out isConnected);
toolStripStatusLabel1.Text = "Total cost: " + cost.ToString();
string txt;
if (isConnected)
{
txt = "Connected. ";
}
else
{
txt = "Not connected. ";
}
txt += "Total cost: " + cost.ToString();
toolStripStatusLabel1.Text = txt;
Console.WriteLine(txt);
// Redraw the network.
networkPictureBox.Refresh();
}
}
else if (Mode == Modes.MinimalSpanningTree)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
// Build a spanning tree.
bool isConnected;
float cost = TheNetwork.MakeMinimalSpanningTree(node, out isConnected);
string txt;
if (isConnected)
{
txt = "Connected. ";
}
else
{
txt = "Not connected. ";
}
txt += "Total cost: " + cost.ToString();
toolStripStatusLabel1.Text = txt;
Console.WriteLine(txt);
// Redraw the network.
networkPictureBox.Refresh();
}
}
else if (Mode == Modes.AnyPath)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
if (e.Button == MouseButtons.Left)
{
Node0 = node;
}
else
{
Node1 = node;
}
// See if we have both nodes.
if ((Node0 != null) && (Node1 != null))
{
// Find a path between the nodes.
List <NetworkNode> pathNodes;
List <NetworkLink> pathLinks;
int cost = TheNetwork.FindAnyPath(Node0, Node1,
out pathNodes, out pathLinks);
string txt = "Path: ";
foreach (NetworkNode pathNode in pathNodes)
{
txt += pathNode.Name + " ";
}
txt += "Total cost: " + cost.ToString();
toolStripStatusLabel1.Text = txt;
Console.WriteLine(txt);
// Redraw the network.
networkPictureBox.Refresh();
}
}
}
else if (Mode == Modes.LabelSettingTree)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
// Build a label setting shortest path tree.
float cost = TheNetwork.FindLabelSettingPathTree(node);
string txt = "Total cost: " + cost.ToString();
toolStripStatusLabel1.Text = txt;
Console.WriteLine(txt);
// Redraw the network.
networkPictureBox.Refresh();
}
}
else if (Mode == Modes.LabelSettingPath)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
if (e.Button == MouseButtons.Left)
{
Node0 = node;
}
else
{
Node1 = node;
}
// See if we have both nodes.
if ((Node0 != null) && (Node1 != null))
{
// Find a path between the nodes.
List <NetworkNode> pathNodes;
List <NetworkLink> pathLinks;
int cost = TheNetwork.FindLabelSettingPath(Node0, Node1,
out pathNodes, out pathLinks);
string txt = "Path: ";
foreach (NetworkNode pathNode in pathNodes)
{
txt += pathNode.Name + " ";
}
txt += "Total cost: " + cost.ToString();
toolStripStatusLabel1.Text = txt;
Console.WriteLine(txt);
// Redraw the network.
networkPictureBox.Refresh();
}
}
}
else if (Mode == Modes.LabelCorrectingTree)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
// Build a label setting shortest path tree.
float cost = TheNetwork.FindLabelCorrectingPathTree(node);
string txt = "Total cost: " + cost.ToString();
toolStripStatusLabel1.Text = txt;
Console.WriteLine(txt);
// Redraw the network.
networkPictureBox.Refresh();
}
}
else if (Mode == Modes.LabelCorrectingPath)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
if (e.Button == MouseButtons.Left)
{
Node0 = node;
}
else
{
Node1 = node;
}
// See if we have both nodes.
if ((Node0 != null) && (Node1 != null))
{
// Find a path between the nodes.
List <NetworkNode> pathNodes;
List <NetworkLink> pathLinks;
int cost = TheNetwork.FindLabelCorrectingPath(Node0, Node1,
out pathNodes, out pathLinks);
string txt = "Path: ";
foreach (NetworkNode pathNode in pathNodes)
{
txt += pathNode.Name + " ";
}
txt += "Total cost: " + cost.ToString();
toolStripStatusLabel1.Text = txt;
Console.WriteLine(txt);
// Redraw the network.
networkPictureBox.Refresh();
}
}
}
else if (Mode == Modes.MaximalFlow)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
if (e.Button == MouseButtons.Left)
{
Node0 = node;
}
else
{
Node1 = node;
}
// See if we have both nodes.
if ((Node0 != null) && (Node1 != null))
{
// Calculate the maximal flow.
int flow = TheNetwork.MaximalFlow(Node0, Node1);
// Redraw.
networkPictureBox.Refresh();
// Display the result.
string txt = "Total flow " + Node0.ToString() +
"-->" + Node1.ToString() + ": " + flow;
Console.WriteLine(txt);
MessageBox.Show(txt);
// We're done with these nodes.
Node0 = null;
Node1 = null;
}
}
}
else if (Mode == Modes.MinFlowCut)
{
// See if there is a node here.
NetworkNode node = TheNetwork.FindNode(e.Location);
if (node == null)
{
SystemSounds.Beep.Play();
}
else
{
if (e.Button == MouseButtons.Left)
{
Node0 = node;
}
else
{
Node1 = node;
}
// See if we have both nodes.
if ((Node0 != null) && (Node1 != null))
{
// Find a minimal flow cut.
int flow = TheNetwork.MinimalFlowCut(Node0, Node1);
// Redraw.
networkPictureBox.Refresh();
// Display the result.
string txt = "Minimal flow cut " + Node0.ToString() +
"-->" + Node1.ToString() + ": " + flow;
Console.WriteLine(txt);
MessageBox.Show(txt);
// We're done with these nodes.
Node0 = null;
Node1 = null;
}
}
}
}