力扣 145. 二叉树的后序遍历 递归 迭代

标签：145 TreeNode val 力扣 right 二叉树 left root result

递归

/**  * 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> postorderTraversal(TreeNode root) {         List<Integer> result = new ArrayList<>();         preorder(root,result);         return result;     }     void preorder(TreeNode root,List<Integer> result){         if(root==null){             return;         }         preorder(root.left,result);         preorder(root.right,result);         result.add(root.val);     } }   迭代    

标签：145,TreeNode,val,力扣,right,二叉树,left,root,result
From： https://www.cnblogs.com/JavaYuYin/p/18014076