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

euler_tour/expressions/AdditionOperator.java

@@ -0,0 +1,16 @@
+package euler_tour.expressions;
+
+/**
+ * Created with MONSTER.
+ * User: xgiovio
+ * Date: 27/04/2014
+ * Time: 13:08
+ */
+public class AdditionOperator extends ExpressionOperator {
+    public Integer getValue() {
+        return (firstOperand + secondOperand);
+    }
+    public String toString() {
+        return new String("+"); }
+
+}