continuata implementazione di graph. bfs dfs kruskal dijkstra

graph/Kruskal.java

@@ -0,0 +1,52 @@
+package graph;
+
+
+import partition.ListPartition;
+import partition.Partition;
+import position.NodePositionList;
+import position.PositionList;
+import priorityqueue.Entry;
+import priorityqueue.PriorityQueue;
+import priorityqueue.heap.HeapPriorityQueue;
+
+import java.security.InvalidKeyException;
+
+public class Kruskal<V, E> {
+    protected Graph<V, E> graph;
+    protected Object WEIGHT;
+    protected PositionList<Edge<E>> EList;
+
+    protected PriorityQueue<Double, Edge<E>> Q;
+
+    public Iterable<Edge<E>> execute(Graph<V, E> g, Object w) throws InvalidKeyException{
+	graph = g;
+	WEIGHT = w;
+	Q = new HeapPriorityQueue<Double, Edge<E>>();
+	EList = new NodePositionList<Edge<E>>();
+	KruskalAlg();
+	return EList;
+    }
+
+    protected void KruskalAlg() throws InvalidKeyException{
+	Partition<Vertex<V>> P = new ListPartition<Vertex<V>>();
+
+	for (Vertex<V> w : graph.vertices())
+	    P.makeSet(w);
+
+	for (Edge<E> e : graph.edges())
+	    Q.insert((Double) e.get(WEIGHT), e);
+
+	while (EList.size() < graph.numVertices() - 1) {
+	    Entry<Double, Edge<E>> e_entry = Q.removeMin();
+	    Edge<E> e = e_entry.getValue();
+	    Vertex<V> endV[] = graph.endVertices(e);
+	    Vertex<V> u = endV[0];
+	    Vertex<V> v = endV[1];
+
+	    if (P.find(u) != P.find(v)) {
+		P.union(P.find(u), P.find(v));
+		EList.addLast(e);
+	    }
+	}
+    }
+}