binary-tree-inorder-traversal.py

#Time Complexity:   O(n)
#Space Complexity:  O(n)
#Speed: 78.92%
#Memory: 99.97%

# 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: TreeNode) -> List[int]:
        if root is None:
            return []
        else:
            return self.inorderTraversal(root.left) + [root.val] + self.inorderTraversal(root.right)