94. Binary Tree Inorder Traversal

Given a binary tree, return the inorder traversal of its nodes' values.

Example:

Input: [1,null,2,3]
1

2
/
3

Output: [1,3,2]

Follow up: Recursive solution is trivial, could you do it iteratively?

# 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):
        """
        :type root: TreeNode
        :rtype: List[int]
        """
        list = []
        def inorder(root):
            if root.left:
                inorder(root.left)
            list.append(root.val)
            if root.right:
                inorder(root.right)
        try:
            inorder(root)
            return list
        except:
            return list