java 二叉树递归遍历算法

 //递归中序遍历
    public void inorder() {
        System.out.print("binaryTree递归中序遍历:");
        inorderTraverseRecursion(root);
        System.out.println();
    }

    //层次遍历
    public void layerorder() {
        System.out.print("binaryTree层次遍历:");
        LinkedList<Node<Integer>> queue = new LinkedList<Node<Integer>>();
        queue.addLast(root);
        Node<Integer> current = null;
        while(!queue.isEmpty()) {
            current = queue.removeFirst();
            if (current.getLeftChild() != null)
                queue.addLast(current.getLeftChild());
            if (current.getRightChild() != null)
                queue.addLast(current.getRightChild());
            System.out.print(current.getValue());
        }
        System.out.println();
    }


    //获得二叉树深度
    public int getDepth() {
        return getDepthRecursion(root);
    }

    private int getDepthRecursion(Node<Integer> node){
        if (node == null)
            return 0;
        int llen = getDepthRecursion(node.getLeftChild());
        int rlen = getDepthRecursion(node.getRightChild());
        int maxlen = Math.max(llen, rlen);
        return maxlen + 1;
    }
    //递归先序遍历
    public void preorder() {
        System.out.print("binaryTree递归先序遍历:");
        preorderTraverseRecursion(root);
        System.out.println();
    }