🟡 剑指 Offer 36. 二叉搜索树与双向链表

LeetCode 提示

题目难度 中等

原题链接 🔗 leetcode

题解 1_偷瞄了.py

"""# Definition for a Node.class Node:    def __init__(self, val, left=None, right=None):        self.val = val        self.left = left        self.right = right"""class Solution:    def treeToDoublyList(self, root: 'Node') -> 'Node':        if not root:            return None        self.pre, self.cur = None, None        self.head = None
        def visit(node):            if not node:                return            visit(node.left)            # visit node            self.cur = node            if self.pre:                self.pre.right = self.cur                self.cur.left = self.pre            else:                self.head = self.cur            self.pre = self.cur            visit(node.right)
        visit(root)        self.head.left = self.pre        self.pre.right = self.head        return self.head