From 9a778586f398a0c807a4469410936c573bc2e6ef Mon Sep 17 00:00:00 2001
From: Gianluca <gianlucamastrolonardo10@gmail.com>
Date: Mon, 29 Apr 2024 21:31:37 +0200
Subject: [PATCH] fixed Lab5
---
Algoritmi_2/Laboratorio/Lab5/Test/TestLab.java | 5 ++++-
Algoritmi_2/Laboratorio/Lab5/src/DFS.java | 18 ++++++++----------
2 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/Algoritmi_2/Laboratorio/Lab5/Test/TestLab.java b/Algoritmi_2/Laboratorio/Lab5/Test/TestLab.java
index a058fc4..7aaaf0d 100644
--- a/Algoritmi_2/Laboratorio/Lab5/Test/TestLab.java
+++ b/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());
diff --git a/Algoritmi_2/Laboratorio/Lab5/src/DFS.java b/Algoritmi_2/Laboratorio/Lab5/src/DFS.java
index a5a2aa7..4dd95fc 100644
--- a/Algoritmi_2/Laboratorio/Lab5/src/DFS.java
+++ b/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;
--
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