递归实现前序、中序、后序遍历,用List进行存储 Stream流化将List转为int[] import java.util.*; /* * public class TreeNode { * int val = 0; * TreeNode left = null; * TreeNode right = null; * } */ public class Solution { /** * * @param root TreeNode类 the root of binary tree * @return int整型二维数组 ...