1. Description One way to serialize a binary tree is to use pre-order traversal. When we encounter a non-null node, we record the node's value. If it is a null node, we record using a sentinel value such as #. _9_ / \ 3 2 / \ / \ 4 1 # 6 / \ / \ / \…

题目: Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes v and w as the lowest node in T that has both v a…

[LeetCode]331. Verify Preorder Serialization of a Binary Tree 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree/description/ 题目描述: One way to serialize a binary tree is to use pre-order traver…

传送门 331. Verify Preorder Serialization of a Binary Tree My Submissions QuestionEditorial Solution Total Accepted: 10790 Total Submissions: 34071 Difficulty: Medium One way to serialize a binary tree is to use pre-order traversal. When we encounter a…

331. 验证二叉树的前序序列化 331. Verify Preorder Serialization of a Binary Tree 题目描述 每日一算法2019/5/30Day 27LeetCode331. Verify Preorder Serialization of a Binary Tree…

[LeetCode]449. Serialize and Deserialize BST 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/serialize-and-deserialize-bst/description/ 题目描述: Serialization is the process of converting a data structure or object into a sequence of bits s…

[LeetCode]779. K-th Symbol in Grammar 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/k-th-symbol-in-grammar/description/ 题目描述: On the first row, we write a 0. Now in every subsequent row, we lo…

[LeetCode]792. Number of Matching Subsequences 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/number-of-matching-subsequences/description/ 题目描述: Given string S and a dictionary of words words,…

[LeetCode]881. Boats to Save People 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/boats-to-save-people/description/ 题目描述: The i-th person has weight people[i], and each boat can carry a maximu…

[LeetCode]802. Find Eventual Safe States 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/find-eventual-safe-states/description/ 题目描述: In a directed graph, we start at some node and every turn, w…