题目来源
https://leetcode.com/problems/binary-tree-inorder-traversal/
iven a binary tree, return the inorder traversal of its nodes' values.
For example:
Given binary tree {1,#,2,3},
1
\
2
/
3
return [1,3,2].
题意分析
Input:tree
Output: inorder traversal
Conditions:中序遍历，要非递归
题目思路
非递归实现
AC代码（Python）
# 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 iterative_inorder(self, root, list):
stack = []
while root or stack:
if root:
stack.append(root)
root = root.left
else:
root = stack.pop()
list.append(root.val)
root = root.right
return list def recursive_inorder(self, root, list):
if root:
self.inorder(root.left, list)
list.append(root.val)
self.inorder(root.right, list) def inorderTraversal(self, root):
list = []
self.iterative_inorder(root, list)
return list