[LeetCode]题解（python）：114 Flatten Binary Tree to Linked List

题目来源

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https://leetcode.com/problems/flatten-binary-tree-to-linked-list/

Given a binary tree, flatten it to a linked list in-place.

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题意分析

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Input: binary tree

Output: flattened tree

Conditions:将一个二叉树压平为一个flatten 树，也就是一条斜线

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题目思路

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先将左右子树压平，然后将左子树嵌入到本节点与右子树之间。

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AC代码（Python）

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

 class Solution(object):
     def flatten(self, root):
         """
         :type root: TreeNode
         :rtype: void Do not return anything, modify root in-place instead.
         """
         if root == None:
             return
         self.flatten(root.left)
         self.flatten(root.right)
         p = root
         if p.left == None:
             return
         p = p.left
         while p.right:
             p = p.right
         p.right = root.right
         root.right = root.left
         root.left = None