fixed Lab5

Algoritmi_2/Laboratorio/Lab5/Test/TestLab.java

@@ -72,11 +72,14 @@ class TestLab {
         DFS dfsTest = new DFS(dag);
         Assertions.assertTrue(dfsTest.topologicalOrderDag().indexOf(0) < dfsTest.topologicalOrder().indexOf(3));
 
+        System.out.println(dfsTest.hasDirCycle());
+
         DirectedGraph cyclicGraph = new DirectedGraph("3; 0 1; 1 2; 2 0");
         DFS dfsCyclicTest = new DFS(cyclicGraph);
+        System.out.println(dfsCyclicTest.hasDirCycle());
         Assertions.assertThrows(IllegalArgumentException.class, () -> dfsCyclicTest.topologicalOrderDag());
 
-        //Da sistemare, bisogna usare ordine fine visita invece che array di padri (per grafi orientati)
+        // Ora funziona anche con questo grafo
         DirectedGraph cyclicGraph2 = new DirectedGraph("2; 0 1; 1 0;");
         DFS dfsCyclicTest2 = new DFS(cyclicGraph2);
         Assertions.assertThrows(IllegalArgumentException.class, () -> dfsCyclicTest2.topologicalOrderDag());

Algoritmi_2/Laboratorio/Lab5/src/DFS.java

@@ -12,7 +12,7 @@ class DFS {
     private GraphInterface myGraph;
     private boolean[] founded;
     private GraphInterface treeDFS;
-    private int[] fathers;
+    private ArrayList<Integer> terminated = new ArrayList<>();
 
     private ArrayList<Integer> postVisitOrder = new ArrayList<>();
 
@@ -66,16 +66,16 @@ class DFS {
     private
     boolean hasDirCycleImpl(int sorg) {
         founded[sorg] = true;
-        for (Integer node : myGraph.getNeighbors(sorg)) {
-            if (!founded[node]) {
-                fathers[node] = sorg;
-                if (hasDirCycleImpl(node)) {
-                    return true;
+        for (int neighbour : myGraph.getNeighbors(sorg)) {
+            if (!founded[neighbour]) {
+                if (hasDirCycleImpl(neighbour)) { // Check the result of the recursive call
+                    return true; // If a cycle is detected in the recursive call, propagate it up
                 }
-            } else if (fathers[sorg] != -1 && node != fathers[sorg]) {
+            } else if (!terminated.contains(neighbour)) {
                 return true;
             }
         }
+        terminated.add(sorg);
         return false;
     }
 
@@ -85,9 +85,7 @@ class DFS {
             throw new IllegalArgumentException("Impossibile usare hasDirCycle su un grafo non orientato");
         }
         for (int i = 0; i < myGraph.getOrder(); i++) {
-            fathers = new int[myGraph.getOrder()];
-            Arrays.fill(fathers, -1);
-            founded = new boolean[myGraph.getOrder()];
+            terminated.clear();
             Arrays.fill(founded, false);
             if (hasDirCycleImpl(i)) {
                 return true;