leetcode刷题三十八

题目叙述

​​https://leetcode-cn.com/problems/binary-tree-inorder-traversal/​​

给定一个二叉树的根节点 root ，返回 它的 中序 遍历 。

题目解答

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def inorderTraversal(self, root: Optional[TreeNode]) -> List[int]:
        L = []      
        def t(node): 
            if node.left:
                t(node.left)
            L.append(node.val)
            if node.right :
                t(node.right)
        if not root:
            pass
        else:
            t(root)
        return      

题目运行结果