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…
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 / \ / \ / \ # # # # # # For…
331. 验证二叉树的前序序列化 序列化二叉树的一种方法是使用前序遍历.当我们遇到一个非空节点时,我们可以记录下这个节点的值.如果它是一个空节点,我们可以使用一个标记值记录,例如 #. _9_ / \ 3 2 / \ / \ 4 1 # 6 / \ / \ / \ # # # # # # 例如,上面的二叉树可以被序列化为字符串 "9,3,4,#,#,1,#,#,2,#,6,#,#",其中 # 代表一个空节点. 给定一串以逗号分隔的序列,验证它是否是正确的二叉树的前序序列化.编写一个在不…
验证二叉树的前序序列化 序列化二叉树的一种方法是使用前序遍历.当我们遇到一个非空节点时,我们可以记录下这个节点的值.如果它是一个空节点,我们可以使用一个标记值记录,例如#. 例如,上面的二叉树可以被序列化为字符串"9,3,4,#,#,1,#,#,2,#,6,#,#",其中#代表一个空节点. 给定一串以逗号分隔的序列,验证它是否是正确的二叉树的前序序列化.编写一个在不重构树的条件下的可行算法. 每个以逗号分隔的字符或为一个整数或为一个表示null指针的'#'. 你可以认为输入格式总是有效…
[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…
序列化二叉树的一种方法是使用前序遍历.当我们遇到一个非空节点时,我们可以记录这个节点的值.如果它是一个空节点,我们可以使用一个标记值,例如 #.     _9_    /   \   3     2  / \   / \ 4   1  #  6/ \ / \   / \# # # #   # #例如,上面的二叉树可以被序列化为字符串"9,3,4,#,#,1,#,#,2,#,6,#,#",其中#代表一个空节点.给定一串以逗号分隔的值,验证它是否是正确的二叉树的前序序列化.想出一种在不重构…
One way to serialize a binary tree is to use pre-oder 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 / \ / \ / \ # # # # # # For…
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 / \ / \ / \…
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 / \ / \ / \ # # # # # # For…
题目如下: 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 / \ / \ / \ # # # # #…
原题链接在这里:https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree/ 题目: 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…
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 / \ / \ / \ # # # # # # For…
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 / \ / \ / \ # # # # # # For…
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_ / \ / \ / \ # / \ / \ / \ # # # # # # For example,…
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 / \ / \ / \ # # # # # # For…
2018-07-31 17:47:13 问题描述: 问题求解: 本题要求在不构建二叉树的情况下对先序遍历生成的序列化字符串进行合法性验证,这里有个技巧性较强的验证方法,就是采用当前可用的指针数目进行验证,最初的时候只有一个指针,每当遇到一个节点,那么需要消耗一个指针,同时,如果是非空节点需要额外增加两个指针.在遍历过程中一旦出现了指针数目为负数的情况,那么就可以直接判false,最后如果指针数目不为0的话,也直接判false.(这里默认如果序列化为空字符串,则直接判false) public b…
简单粗暴,代码有待优化,不过自己独立完成,没有参考任何材料,还是比较满意的 package y2019.Algorithm.stack.medium; import java.util.Stack; /** * @Auther: xiaof * @Date: 2019/12/6 09:06 * @Description:331. 验证二叉树的前序序列化 * * 序列化二叉树的一种方法是使用前序遍历.当我们遇到一个非空节点时,我们可以记录下这个节点的值.如果它是一个空节点, * 我们可以使用一个标…
一.题目描述 序列化二叉树的一种方法是使用前序遍历.当我们遇到一个非空节点时,我们可以记录下这个节点的值.如果它是一个空节点,我们可以使用一个标记值记录,例如 #. _9_ / \ 3 2 / \ / \ 4 1 # 6 / \ / \ / \ # # # # # # 例如,上面的二叉树可以被序列化为字符串 "9,3,4,#,#,1,#,#,2,#,6,#,#",其中 # 代表一个空节点. 给定一串以逗号分隔的序列,验证它是否是正确的二叉树的前序序列化.编写一个在不重构树的条件下的可行…
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 / \ / \ / \ # # # # # # For…
144. 二叉树的前序遍历 知识点:二叉树:递归:Morris遍历 题目描述 给你二叉树的根节点 root ,返回它节点值的 前序 遍历. 示例 输入:root = [1,null,2,3] 输出:[1,2,3] 输入:root = [] 输出:[] 输入:root = [1] 输出:[1] 输入:root = [1,2] 输出:[1,2] 输入:root = [1,null,2] 输出:[1,2] 解法一:递归 /** * Definition for a binary tree node.…
Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another comput…
144. Binary Tree Preorder Traversal 前序的非递归遍历:用堆来实现 如果把这个代码改成先向堆存储左节点再存储右节点,就变成了每一行从右向左打印 如果用队列替代堆,并且先存储左节点,再存储右节点,就变成了逐行打印 class Solution { public: vector<int> preorderTraversal(TreeNode* root) { vector<int> result; if(root == NULL) return res…
地址 https://leetcode-cn.com/contest/weekly-contest-163/problems/find-elements-in-a-contaminated-binary-tree/ 题目描述给出一个满足下述规则的二叉树: root.val == 0如果 treeNode.val == x 且 treeNode.left != null,那么 treeNode.left.val == 2 * x + 1如果 treeNode.val == x 且 treeNode…
今天做了三道LeetCode上的简单题目,每道题都是用c++和Python两种语言写的.由于c++版的代码网上比較多.所以就仅仅分享一下Python的代码吧,刚学完Python的基本的语法,做做LeetCode的题目还是不错的,对以后找工作面试也有帮助! 刚開始就从AC率最高的入手吧! 1.Given an array of integers, every element appears twice except for one. Find that single one. Note: Your…
问题 该文章的最新版本已迁移至个人博客[比特飞],单击链接 https://www.byteflying.com/archives/4072 访问. 给定一个二叉树,找出其最大深度. 二叉树的深度为根节点到最远叶子节点的最长路径上的节点数. 说明: 叶子节点是指没有子节点的节点. 给定二叉树 [3,9,20,null,null,15,7], 3       / \    9   20   /        \ 15        7 返回它的最大深度 3 . Given a binary tre…
Given a binary tree, return the preorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3]. Note: Recursive solution is trivial, could you do it iteratively? 一般我们提到树的遍历,最常见的有先序遍历,中序遍历,后序遍历和层序遍历,它们用递归实现起…
Given a binary tree where all the right nodes are either leaf nodes with a sibling (a left node that shares the same parent node) or empty, flip it upside down and turn it into a tree where the original right nodes turned into left leaf nodes. Return…
Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example:Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1 return true…
Given a binary tree, return the preorder traversal of its nodes' values. Example: Input: [1,null,2,3] 1 \ 2 / 3 Output: [1,2,3] Follow up: Recursive solution is trivial, could you do it iteratively? ---------------------------------------------------…