solved Task 4

src/ch/zhaw/ads/ADS7_4_test.java

@@ -22,7 +22,7 @@ public class ADS7_4_test {
     String fileToTest = "RouteServer.java";
 
     @BeforeEach
-    private void init() throws Exception {
+    void init() throws Exception {
         String swiss = "Winterthur Zürich 25\n" +
                 "Zürich Bern 126\n" +
                 "Zürich Genf 277\n" +

src/ch/zhaw/ads/RouteServer.java

@@ -27,6 +27,34 @@ public class RouteServer implements CommandExecutor {
     apply the dijkstra algorithm
     */
     public void dijkstraRoute(Graph<DijkstraNode, Edge> graph, String from, String to) {
+        for(DijkstraNode node : graph.getNodes()){
+            node.setMark(false);
+            node.setDist(Double.MAX_VALUE);
+            node.setPrev(null);
+        }
+
+        DijkstraNode currentNode = graph.findNode(from);
+        DijkstraNode goalNode = graph.findNode(to);
+        Queue<DijkstraNode> redNodes = new PriorityQueue<>();
+        currentNode.setDist(0);
+        redNodes.add(currentNode);
+        while(!redNodes.isEmpty()){
+            currentNode = redNodes.remove();
+            if(currentNode == goalNode){ return; }
+            currentNode.setMark(true);
+            for(Edge edge : currentNode.getEdges()){
+                DijkstraNode neighbour = (DijkstraNode) edge.getDest();
+                if(!neighbour.getMark()){
+                    double dist = currentNode.getDist() + edge.getWeight();
+                    if(dist < neighbour.getDist()) {
+                        neighbour.setDist(dist);
+                        neighbour.setPrev(currentNode);
+                        redNodes.remove(neighbour);
+                        redNodes.add(neighbour);
+                    }
+                }
+            }
+        }
         // TODO implement
     }