uebung03

uebung03/src/graph/Graph.java

@@ -0,0 +1,70 @@
+package graph;
+
+import java.util.ArrayList;
+
+public class Graph {
+    private ArrayList<Node> nodes;
+
+    public ArrayList<Node> getNodes() {
+        return nodes;
+    }
+
+    public Node getFirstNode() {
+        return nodes.get(0);
+    }
+
+    public void addNode(Node n) {
+        if (nodes.contains(n)) {
+            throw new IllegalArgumentException();
+        }
+        nodes.add(n);
+    }
+
+    public ArrayList<Node> depthFirst(Node startNode) {
+        unmarkAllNodes();
+        final ArrayList<Node> collect = new ArrayList<>();
+        search(startNode, collect);
+        return collect;
+    }
+
+    private void search(Node node, ArrayList<Node> collect) {
+        if (node.getMarked()) return;
+        node.setMarked(true);
+        collect.add(node);
+        for (Edge e : node.getOut())
+            search(e.getTarget(), collect);
+    }
+
+    public ArrayList<Node> breadthFirst(Node startNode) {
+        unmarkAllNodes();
+        final ArrayList<Node> collect = new ArrayList<>();
+        startNode.setMarked(true);
+        collect.add(startNode);
+        // Die folgende For-Schleife kann nicht als foreach-loop
+        // realisiert werden, weil sich collect laufend ändert
+        for (int i = 0; i < collect.size(); i++)
+            for (Edge edge : collect.get(i).getOut()) {
+                final Node target = edge.getTarget();
+                if (!target.getMarked()) {
+                    target.setMarked(true);
+                    collect.add(target);
+                }
+            }
+        return collect;
+    }
+
+    private void unmarkAllNodes() {
+        for (Node n : nodes)
+            n.setMarked(false);
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder str = new StringBuilder();
+        str.append("Grap=\n");
+        for (Node n : nodes) {
+            str.append(n).append(";\n");
+        }
+        return str.toString();
+    }
+}