Leetcode: Binary Tree Inorder Traversal @Python

Iterative solution:

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

class Solution:
    # @param root, a tree node
    # @return a list of integers
    def inorderTraversal(self, root):
        pstack=[]
        rst=[]
        p=root
        while p or pstack:
            while p:
                pstack.append(p)
                p=p.left
            p=pstack.pop()
            rst.append(p.val)
            p=p.right
        return rst

Recursive solution:

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

class Solution:
    # @param root, a tree node
    # @return a list of integers
    def recur(self, root, rst):
        if not root: return
        self.recur(root.left, rst)
        rst.append(root.val)
        self.recur(root.right,rst)
        return
    def inorderTraversal(self, root):
        rst=[]
        self.recur(root, rst)
        return rst