/**94. 二叉树的中序遍历
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
class Solution {
public List<Integer> inorderTraversal(TreeNode root) {
//TreeNode将数组形式的二叉树录入,建立起树的关系
//root.val,返回当前值
//root.left返回左子节点的值
//root.right返回右字节点的值
//使用递归函数: inorder(root, res);
List<Integer> res = new ArrayList<Integer>();
//类名 对象名=new 类名();用指针的解释就是以无参数构造方法实例化对象并将这个对象的内存引 用赋给“类名”类的“对象名”引用变量
//https://zhidao.baidu.com/question/625450678706878204.html
inorder(root, res);
return res;
}
public void inorder(TreeNode root, List res){
if(root == null)return;
inorder(root.left, res);
res.add(root.val);
inorder(root.right, res);
}
}