94.py

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def inorderTraversal(self, root: TreeNode) -> List[int]:
        self.res = []
        def dfs(node):
            if not node: return
            dfs(node.left)
            self.res.append(node.val)
            dfs(node.right)
        dfs(root)
        return self.res