static void Debug2(WGraph tree2)
{
Console.Write("The list of nodes is: \n");
Console.Write(tree2.ListNodes() + "\n\n");
Console.Write("The graph edgelist is: \n");
Console.Write(tree2.DisplayEdges() + "\n\n");
Console.Write("The graph edge matrix is\n");
Console.Write(tree2.DisplayMatrix() + "\n");
}
public static Dictionary <NodeType, NodeType> FindPath <NodeType>(WGraph <NodeType> graph, NodeType startNode)
{
Dictionary <NodeType, int> weights = new Dictionary <NodeType, int>(); //node weights
Dictionary <NodeType, bool> hasVisited = new Dictionary <NodeType, bool>();
Dictionary <NodeType, NodeType> path = new Dictionary <NodeType, NodeType>();
Queue <NodeType> q = new Queue <NodeType>();
q.Enqueue(startNode);
weights.Add(startNode, 0);
while (q.Count != 0)
{
NodeType n = q.Peek();
if (!hasVisited.ContainsKey(n))
{
hasVisited.Add(n, true);
q.Dequeue();
foreach (var neighbor in graph.Neighbors(n))
{
if (weights.ContainsKey(neighbor))
{
if (weights[neighbor] > graph.getW(neighbor) + weights[n])
{
weights[neighbor] = graph.getW(neighbor) + weights[n];
path[neighbor] = n;
}
}
else
{
weights[neighbor] = graph.getW(neighbor) + weights[n];
path[neighbor] = n;
}
if (!hasVisited.ContainsKey(neighbor))
{
q.Enqueue(neighbor);
}
}
}
else
{
q.Dequeue();
}
}
return(path);
}
public static List <NodeType> GetPath <NodeType>(WGraph <NodeType> graph, NodeType startNode, NodeType endNode)
{
List <NodeType> path = new List <NodeType>();
Dictionary <NodeType, NodeType> full_path = FindPath <NodeType>(graph, startNode);
if (full_path.ContainsKey(endNode))
{
NodeType td = endNode;
path.Insert(0, td); //
while (!path[0].Equals(startNode))
{
td = full_path[td];
path.Insert(0, td);
}
}
return(path);
}
static void MinCostTest()
{
Console.Write("This test displays a minimum cost spanning tree for a weighted graph\n\n");
// create the graph
WGraph tree2 = new WGraph();
// add nodes
tree2.AddNode('A');
tree2.AddNode('C');
tree2.AddNode('T');
tree2.AddNode('Z');
tree2.AddNode('X');
tree2.AddNode('K');
tree2.AddNode('Q');
tree2.AddNode('J');
tree2.AddNode('M');
tree2.AddNode('U');
// add edges
tree2.AddWEdge('A', 'C', 3);
tree2.AddWEdge('A', 'T', 4);
tree2.AddWEdge('A', 'Z', 2);
tree2.AddWEdge('X', 'C', 4);
tree2.AddWEdge('C', 'K', 8);
tree2.AddWEdge('T', 'Q', 4);
tree2.AddWEdge('K', 'Q', 3);
tree2.AddWEdge('Q', 'J', 6);
tree2.AddWEdge('J', 'M', 5);
tree2.AddWEdge('Z', 'X', 6);
// uncomment the next line to see your node list, edge list, and edge matrix
Debug2(tree2);
Console.Write("The min cost tree should be: \n");
Console.Write("Q: Q-K Q-T T-A A-Z A-C C-X Q-J J-M \n");
Console.Write("The min cost tree is: \n");
Console.Write(tree2.MinCostTree('Q') + "\n");
Console.Write("Done with testing min cost spanning tree \n\n");
}