1 **
2 * Binary tree first-order traversal non-recursive
3 * @param root
4 */
5 public void preOrder_no_recursive(TreeNode root){
6 if(root == null) return;
7
8 Stack stack = new Sta
1 **
2 * Binary tree first-order traversal non-recursive
3 * @param root
4 */
5 public void preOrder_no_recursive(TreeNode root){
6 if(root == null) return;
7
8 Stack stack = new Sta