[LeetCode]94 二叉树的中序遍历

题目描述

给定一个二叉树，返回它的中序 遍历。

示例:

输入: [1,null,2,3]
   1
    \
     2
    /
   3
输出: [1,3,2]

代码

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# 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]
        """
        if root == None:
            return []
        result=[]
        stack = [root]
        cur =root
        while stack:
            while cur.left!= None:
                cur = cur.left
                stack.append(cur)
            node = stack.pop()
            result.append(node.val)
            if node.right:
                cur = node.right
                stack.append(cur)
        return result