edit 145

fishercoder1534 · fishercoder1534 · commit 828706274880 · 2017-07-31T10:05:09.000-07:00
diff --git a/src/main/java/com/fishercoder/solutions/_145.java b/src/main/java/com/fishercoder/solutions/_145.java
@@ -24,8 +24,8 @@ public class _145 {
 	/**A tricky one: Modify the code for pre-order traversal so that it becomes root->right->left, and then reverse the result to get left->right->root.*/
     public static List<Integer> postorderTraversal_iterative(TreeNode root) {
         List<Integer> result = new ArrayList();
-        Stack<TreeNode> stack = new Stack();
         if(root == null) return result;
+        Stack<TreeNode> stack = new Stack();
         stack.push(root);
         while(!stack.isEmpty()){
             root = stack.pop();
