/**  
         * 逆向逐层输出树中的元素  
         *  
         * @className: LevelOrderTraversalInReverse  
         * @author: Max Solider  
         * @date: 2023-06-11 18:35  
         */public class LevelOrderTraversalInReverse {  

            public static void levelOrderTraversalInReverse(BinaryTreeNode root) {  
                if (root == null) {  
                    return;  
                }  
                ArrayQueue queue = new ArrayQueue(20);  
                LLStack stack = new LLStack();  
                queue.enQueue(root);  
                while (!queue.isEmpty()) {  
                    BinaryTreeNode tmp = (BinaryTreeNode)queue.deQueue();  
                    if (tmp.getLeft() != null) {  
                        queue.enQueue(tmp.getLeft());  
                    }  
                    if (tmp.getRight() != null) {  
                        queue.enQueue(tmp.getRight());  
                    }  
                    stack.push(String.valueOf(tmp.getData()));  
                }  
                while (!stack.isEmpty()) {  
                    System.out.println(stack.pop());  
                }  
            }  

            public static void main(String[] args) {  
                BinaryTreeNode node4 = new BinaryTreeNode(4, null, null);  
                BinaryTreeNode node5 = new BinaryTreeNode(5, null, null);  
                BinaryTreeNode node6 = new BinaryTreeNode(6, null, null);  
                BinaryTreeNode node7 = new BinaryTreeNode(7, null, null);  
                BinaryTreeNode node2 = new BinaryTreeNode(2, node4, node5);  
                BinaryTreeNode node3 = new BinaryTreeNode(3, node6, node7);  
                BinaryTreeNode node1 = new BinaryTreeNode(1, node2, node3);  
                levelOrderTraversalInReverse(node1);  
            }  
        }