Init

- init with the first interface and tests
- added some basic class for the tests

src/berack96/sim/util/graph/visit/DFS.java

@@ -0,0 +1,58 @@
+package berack96.sim.util.graph.visit;
+
+import berack96.sim.util.graph.Graph;
+
+import java.util.Iterator;
+import java.util.Stack;
+import java.util.function.Consumer;
+
+/**
+ * Depth-first search<br>
+ * The algorithm starts at the root node and explores as far as possible along each branch before backtracking.
+ *
+ * @param <V> the vertex of the graph
+ * @param <W> the weight of the graph
+ */
+public class DFS<V, W extends Number> implements VisitStrategy<V, W> {
+
+    private VisitInfo<V> lastVisit = null;
+
+    /**
+     * Retrieve the info of the last visit
+     *
+     * @return an info of the visit
+     */
+    public VisitInfo<V> getLastVisit() {
+        return lastVisit;
+    }
+
+    @Override
+    public void visit(Graph<V, W> graph, V source, Consumer<V> visit) throws NullPointerException, IllegalArgumentException {
+        lastVisit = new VisitInfo<>(source);
+        final Stack<V> toVisit = new Stack<>();
+
+        toVisit.push(source);
+
+        while (!toVisit.isEmpty()) {
+            V current = toVisit.peek();
+            boolean hasChildToVisit = false;
+            Iterator<V> iter = graph.getChildren(current).iterator();
+
+            while (iter.hasNext() && !hasChildToVisit) {
+                V child = iter.next();
+                if (!lastVisit.isDiscovered(child)) {
+                    hasChildToVisit = true;
+                    toVisit.push(child);
+                    lastVisit.setParent(current, child);
+                }
+            }
+
+            if (!hasChildToVisit) {
+                toVisit.pop();
+                lastVisit.setVisited(current);
+                if (visit != null)
+                    visit.accept(current);
+            }
+        }
+    }
+}