private static Graph buildgraph()
{
gNode n0 = new gNode(0);
gNode n1 = new gNode(1);
gNode n2 = new gNode(2);
gNode n3 = new gNode(3);
gNode n4 = new gNode(4);
gNode n5 = new gNode(5);
gNode n6 = new gNode(6);
gNode n7 = new gNode(7);
gNode n8 = new gNode(8);
Graph graph = new Graph(n0);
graph.AddEdge(n0, n1, 4);
graph.AddEdge(n0, n7, 8);
graph.AddEdge(n1, n7, 11);
graph.AddEdge(n1, n2, 9);
graph.AddEdge(n2, n8, 2);
graph.AddEdge(n7, n8, 7);
graph.AddEdge(n7, n6, 1);
graph.AddEdge(n8, n6, 6);
graph.AddEdge(n6, n5, 2);
graph.AddEdge(n5, n2, 4);
graph.AddEdge(n2, n3, 7);
graph.AddEdge(n3, n5, 14);
graph.AddEdge(n5, n4, 10);
graph.AddEdge(n3, n4, 9);
return graph;
}
public Graph Prims()
{
Graph minSpan = new Graph(null);
List<gNode> temp = new List<gNode>();
while (nodeList.Count > 0)
{
Heapify(); //place graph in min heap
gNode root = nodeList[0]; //extract node with min key
gNode n = new gNode(root.data);
if (root.parent != null)
{
if (minSpan.start == null)
minSpan.start = root.parent;
minSpan.AddEdge(root.parent, n, root.key);
root.parent = null;
}
for (int i = 0; i < root.adj.Count; i++)
{
if (root.adj[i].key > root.cost[i])
{
root.adj[i].key = root.cost[i];
root.adj[i].parent = n;
}
}
temp.Add(root);
nodeList.RemoveAt(0);
}
nodeList = temp;
return minSpan;
}