LeetCode 刷题【145. 二叉树的后序遍历】

145. 二叉树的后序遍历

自己做

解：递归遍历

/*** 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 {List<Integer> res = new ArrayList();public void postTravel(TreeNode root){if(root == null)return;postTravel(root.left);postTravel(root.right);res.add(root.val);}public List<Integer> postorderTraversal(TreeNode root) {postTravel(root);return res;}
}