Дерево

vol6/src/main/java/ru/mifi/practice/vol6/tree/Main.java

@@ -1,5 +1,6 @@
 package ru.mifi.practice.vol6.tree;
 
+import ru.mifi.practice.vol6.tree.visitors.EulerPath;
 import ru.mifi.practice.vol6.tree.visitors.OnSubTree;
 
 import java.io.IOException;
@@ -9,18 +10,23 @@ public abstract class Main {
     public static void main(String[] args) throws IOException {
         Tree<Integer> tree = new ParserText<Integer>().parse(Main.class.getResourceAsStream("/standard.tree"),
             Integer::parseInt, Comparator.comparing(k -> k));
-        System.out.print("PRE : ");
+        System.out.print("PRE  : ");
         tree.visit(new Visitor.Stdout<>(), new VisitorStrategy.PreOrder<>());
         System.out.println();
-        System.out.print("POST: ");
+        System.out.print("POST : ");
         tree.visit(new Visitor.Stdout<>(), new VisitorStrategy.PostOrder<>());
         System.out.println();
-        System.out.print("IN  : ");
+        System.out.print("IN   : ");
         tree.visit(new Visitor.Stdout<>(), new VisitorStrategy.InOrder<>());
         System.out.println();
         OnSubTree<Integer> on = new OnSubTree<>();
         tree.visit(on, new VisitorStrategy.PreOrder<>());
+        System.out.println("TIMED: ");
         System.out.println(on);
+        EulerPath<Integer> euler = new EulerPath<>();
+        System.out.print("EULER: ");
+        tree.visit(euler, new VisitorStrategy.PreOrder<>());
+        System.out.println(euler);
         System.out.println(tree);
     }
 }

vol6/src/main/java/ru/mifi/practice/vol6/tree/visitors/EulerPath.java

@@ -0,0 +1,45 @@
+package ru.mifi.practice.vol6.tree.visitors;
+
+import ru.mifi.practice.vol6.tree.Node;
+import ru.mifi.practice.vol6.tree.Visitor;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public final class EulerPath<T> implements Visitor<T> {
+    private final List<Node<T>> nodes = new ArrayList<>();
+
+    void clear() {
+        nodes.clear();
+    }
+
+    @Override
+    public void enterNode(Node<T> node) {
+        if (node != null) {
+            nodes.add(node);
+        }
+    }
+
+    @Override
+    public void exitNode(Node<T> node) {
+        if (node != null) {
+            nodes.add(node);
+        }
+    }
+
+    @SuppressWarnings("checked")
+    public List<Node<T>> path() {
+        return nodes;
+    }
+
+
+    @Override
+    public void empty() {
+
+    }
+
+    @Override
+    public String toString() {
+        return String.valueOf(nodes);
+    }
+}