completato binary tree e implementato euler tour astratto + una sua implementazione per computazione aritmetica

euler_tour/expressions/StringExpressionTour.java

@@ -0,0 +1,45 @@
+package euler_tour.expressions;
+
+import euler_tour.EulerTour;
+import position.Position;
+import tree.binarytree.BinaryTree;
+
+/**
+ * Created with MONSTER.
+ * User: xgiovio
+ * Date: 27/04/2014
+ * Time: 13:11
+ */
+public class StringExpressionTour extends EulerTour<ExpressionTerm,String> {
+
+    public String execute(BinaryTree<ExpressionTerm> T) {
+        init(T);
+        return eulerTour(T.root());
+    }
+
+
+
+    protected void visitLeft(Position<ExpressionTerm> v, TourResult<String> r) {
+        if (tree.isInternal(v)) {
+            r.out = new String("(");
+        }else {
+            r.out = new String("");
+        }
+    }
+
+    protected void visitBelow(Position<ExpressionTerm> v, TourResult<String> r) {
+        if (tree.isInternal(v)) {
+            r.out += r.left;
+        }
+        r.out += v.element();
+    }
+
+    protected void visitRight(Position<ExpressionTerm> v,TourResult<String> r) {
+        if (tree.isInternal(v)) {
+            r.out += r.right;
+            r.out += ")";
+        }
+    }
+
+
+}