leetcode刷题-94二叉树的中序遍历

#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def inorderTraversal(self, root: TreeNode) -> List[int]:
        result = []
        def inorder(tree, result):
            if tree != None:
                if tree.left != None:
                    inorder(tree.left, result)
                result.append(tree.val)
                if tree.right != None:
                    inorder(tree.right, result)
        inorder(root, result)
        return result