[leetcode] @python 114. Flatten Binary Tree to Linked List

题目链接

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

题目原文

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

For example,
Given

The flattened tree should look like:

题目大意

将二叉树变成只有有节点的已排好序的树

解题思路

递归，如果有右子树，则将右子树作为该节点左子树的右子树

代码

# 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