to finish

Algoritmi_2/Laboratorio/Lab4/Test/TestGraph.java

@@ -9,7 +9,7 @@ import java.util.Arrays;
 
 public class TestGraph {
     @Test
-    void hasUndirectedCycleTest(){
+    void hasUndirectedCycleTest() {
         UndirectedGraph myGraph = new UndirectedGraph("4; 1 0; 0 2; 2 3; 3 0");
         BFSAndDFSApp testApp = new BFSAndDFSApp(myGraph);
         Assertions.assertTrue(testApp.hasUndirectedCycle());
@@ -22,12 +22,10 @@ public class TestGraph {
     }
 
     @Test
-    void orderPostVisitTest(){
+    void orderPostVisitTest() {
         UndirectedGraph myGraph = new UndirectedGraph("4; 2 0; 1 0; 3 2; 3 1");
         BFSAndDFSApp testApp = new BFSAndDFSApp(myGraph);
         ArrayList<Integer> output = testApp.getNodesInOrderPostVisit(0);
-        System.out.println(output);
-
 
         ArrayList<Integer> expected1 = new ArrayList<>();
 
@@ -37,12 +35,34 @@ public class TestGraph {
         expected1.add(0);
 
         ArrayList<Integer> expected2 = new ArrayList<>();
-        expected1.add(2);
-        expected1.add(3);
-        expected1.add(1);
-        expected1.add(0);
+        expected2.add(2);
+        expected2.add(3);
+        expected2.add(1);
+        expected2.add(0);
+
+        Assertions.assertTrue(output.equals(expected1) || output.equals(expected2));
+    }
+
+    @Test
+    void hasDirCycleTest() {
+        DirectedGraph g = new DirectedGraph("1");
+        BFSAndDFSApp testApp = new BFSAndDFSApp(g);
+        Assertions.assertFalse(testApp.hasDirCycle());
+
+        g = new DirectedGraph("2; 0 1");
+        testApp = new BFSAndDFSApp(g);
+        Assertions.assertFalse(testApp.hasDirCycle());
+
+        g = new DirectedGraph("3; 1 0; 1 2; 0 2");
+        testApp = new BFSAndDFSApp(g);
+        Assertions.assertFalse(testApp.hasDirCycle());
 
+        g = new DirectedGraph("3; 0 2; 2 1; 1 0");
+        testApp = new BFSAndDFSApp(g);
+        Assertions.assertTrue(testApp.hasDirCycle());
 
-Assertions.assertTrue( output.equals(expected1) || output.equals(expected2));
+        g = new DirectedGraph("5; 0 4; 4 1; 4 2; 3 4; 2 3");
+        testApp = new BFSAndDFSApp(g);
+        Assertions.assertTrue(testApp.hasDirCycle());
     }
 }

Algoritmi_2/Laboratorio/Lab4/src/BFSAndDFSApp.java

 import it.uniupo.graphLib.GraphInterface;
+import it.uniupo.graphLib.UndirectedGraph;
 
 import java.util.Arrays;
 import java.util.ArrayList;
@@ -12,7 +13,7 @@ public class BFSAndDFSApp {
     private int[] fathers;
     GraphInterface treeDFS;
 
-    public BFSAndDFSApp(GraphInterface g){
+    public BFSAndDFSApp(GraphInterface g) {
         myGraph = g;
         BFS bfs = new BFS(g);
         DFS dfs = new DFS(g);
@@ -32,8 +33,7 @@ public class BFSAndDFSApp {
                 fathers[node] = node;
                 treeDFS.addEdge(sorg, node);
                 return visitaDFS(node);
-            }
-            else if (node != fathers[node]){
+            } else if (node != fathers[node]) {
                 return true;
             }
         }
@@ -42,7 +42,7 @@ public class BFSAndDFSApp {
 
     public boolean hasUndirectedCycle() {
         for (int nodo = 0; nodo < this.myGraph.getOrder(); nodo++) {
-            if(visitaDFS(nodo)){
+            if (visitaDFS(nodo)) {
                 return true;
             }
         }
@@ -62,9 +62,36 @@ public class BFSAndDFSApp {
         orderPostVisit.add(sorg);
     }
 
-    public ArrayList<Integer> getNodesInOrderPostVisit(int sorg){
+    public ArrayList<Integer> getNodesInOrderPostVisit(int sorg) {
         ArrayList<Integer> orderPostVisit = new ArrayList<>();
         visitaDFSPostVisit(sorg, orderPostVisit);
         return orderPostVisit;
     }
+
+    private boolean hasDirCycleImpl(int sorg) {
+        scoperti[sorg] = true;
+        for (Integer node : myGraph.getNeighbors(sorg)) {
+            if (!scoperti[node]) {
+                fathers[node] = sorg;
+                return hasDirCycleImpl(node);
+            } else if (node != fathers[sorg]) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public boolean hasDirCycle() {
+        if (myGraph instanceof UndirectedGraph) {
+            throw new IllegalArgumentException("Impossibile usare hasDirCycle su un grafo non orientato");
+        }
+        for (int i = 0; i < myGraph.getOrder(); i++) {
+            fathers = new int[myGraph.getOrder()];
+            scoperti = new boolean[myGraph.getOrder()];
+            if (hasDirCycleImpl(i)) {
+                return true;
+            }
+        }
+        return false;
+    }
 }
\ No newline at end of file