code refactoring

Author: Ram swaroop

src/me/ramswaroop/trees/ConstructTreeFromInorderAndPreorder.java

@@ -1,7 +1,6 @@
 package me.ramswaroop.trees;
 
 import me.ramswaroop.common.BinaryNode;
-import me.ramswaroop.common.BinaryTree;
 
 import java.util.List;
 
@@ -12,9 +11,10 @@
  * @date: 6/26/15
  * @time: 5:34 PM
  */
-public class ConstructTreeFromInorderAndPreorder<E extends Comparable<E>> extends BinaryTree<E> {
+public class ConstructTreeFromInOrderAndPreorder {
 
-    public void constructTreeWithInOrderAndPreOrder(List<BinaryNode<E>> inOrder, List<BinaryNode<E>> preOrder) {
+    public <E extends Comparable<E>> void constructTreeWithInOrderAndPreOrder(List<BinaryNode<E>> inOrder,
+                                                                              List<BinaryNode<E>> preOrder) {
         for (int i = 0; i < preOrder.size(); i++) {
 
         }

src/me/ramswaroop/trees/DoubleTree.java

@@ -12,18 +12,16 @@
  * @date: 6/26/15
  * @time: 6:02 PM
  */
-public class DoubleTree<E extends Comparable<E>> extends BinaryTree<E> {
+public class DoubleTree {
 
     /**
      * Converts a given tree to its Double tree. To create a Double tree
      * of the given tree, create a new duplicate for each node, and insert
      * the duplicate as the left child of the original node.
+     * 
+     * @param node
      */
-    public void doubleTree() {
-        doubleTree(root);
-    }
-
-    public void doubleTree(BinaryNode<E> node) {
+    public static <E extends Comparable<E>> void doubleTree(BinaryNode<E> node) {
         if (node == null) return;
 
         BinaryNode<E> newNode = new BinaryNode<>(node.value, node.left, null);
@@ -35,7 +33,7 @@ public void doubleTree(BinaryNode<E> node) {
     }
 
     public static void main(String a[]) {
-        DoubleTree<Integer> bt = new DoubleTree<>();
+        BinaryTree<Integer> bt = new BinaryTree<>();
         bt.put(6);
         bt.put(3);
         bt.put(5);
@@ -44,7 +42,7 @@ public static void main(String a[]) {
         bt.put(9);
         bt.breadthFirstTraversal();
         out.println();
-        bt.doubleTree();
+        doubleTree(bt.root);
         out.println("BFS after Double tree: ");
         bt.breadthFirstTraversal();
     }