1.题目描述 2.问题分析 使用set. 3.代码 set<int> s; int findSecondMinimumValue(TreeNode* root) { dfs(root); vector<int> v; for (set<int>::iterator it = s.begin(); it != s.end(); it++) { v.push_back(*it); } sort(v.begin(), v.end()); ? v[] : -; } void d…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 找出所有值再求次小值 遍历时求次小值 日期 题目地址:https://leetcode.com/problems/second-minimum-node-in-a-binary-tree/description/ 题目描述 Given a non-empty special binary tree consisting of nodes with t…

这是悦乐书的第285次更新,第302篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第153题(顺位题号是671).给定非空的特殊二叉树,其由具有非负值的节点组成,其中该树中的每个节点具有恰好两个或零个子节点. 如果节点具有两个子节点,则该节点的值是其两个子节点中的较小值.给定这样的二叉树,您需要输出由整个树中所有节点的值组成的集合中的第二个最小值.如果不存在这样的第二个最小值,则输出-1.例如: 2 / \ 2 5 / \ 5 7 输出:5 2 / \ 2 2 输出…

题目在这里,要求一个二叉树的倒数第二个小的值.二叉树的特点是父节点的值会小于子节点的值,父节点要么没有子节点,要不左右孩子节点都有. 分析一下,根据定义,跟节点的值肯定是二叉树中最小的值,剩下的只需要找到左右子树中比跟节点大的最小值就可以了.对于这个题目,还是考察的二叉树的搜索,第一印象是BFS.使用一个辅助队列存储遍历过程中的节点,遍历过程中,如果节点的值比结果中第二小的值还大,就不用继续把该节点及其所有的子节点入队了,这样可以节省时间.这里的辅助队列使用的是deque,在两端存取数据的复杂度…

671. 二叉树中第二小的节点 671. Second Minimum Node In a Binary Tree 题目描述 给定一个非空特殊的二叉树,每个节点都是正数,并且每个节点的子节点数量只能为 2 或 0.如果一个节点有两个子节点的话,那么这个节点的值不大于它的子节点的值. 给出这样的一个二叉树,你需要输出所有节点中的第二小的值.如果第二小的值不存在的话,输出 -1. 每日一算法2019/5/12Day 9LeetCode671. Second Minimum Node In a Bin…

problem 671. Second Minimum Node In a Binary Tree 参考 1. Leetcode_easy_671. Second Minimum Node In a Binary Tree; 完…

[leetcode]1379. Find a Corresponding Node of a Binary Tree in a Clone of That Tree 链接 leetcode 描述   Given two binary trees original and cloned and given a reference to a node target in the original tree.   The cloned tree is a copy of the original tr…

原题链接在这里:https://leetcode.com/problems/second-minimum-node-in-a-binary-tree/description/ 题目: Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the n…

Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nodes.…

Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nodes.…

Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nodes.…

题目: Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nod…

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/4100 访问. 给定一个非空特殊的二叉树,每个节点都是正数,并且每个节点的子节点数量只能为 2 或 0.如果一个节点有两个子节点的话,那么这个节点的值不大于它的子节点的值. 给出这样的一个二叉树,你需要输出所有节点中的第二小的值.如果第二小的值不存在的话,输出 -1 . 输入:  2    / \   2   5        / \      5   7 输出:…

Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nodes.…

题目来源 https://leetcode.com/problems/flatten-binary-tree-to-linked-list/ Given a binary tree, flatten it to a linked list in-place. 题意分析 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 题目思路 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.…

题目来源 https://leetcode.com/problems/balanced-binary-tree/ Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never d…

Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-nodes.…

［抄题］: Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly twoor zero sub-node. If the node has two sub-nodes, then this node's value is the smaller value among its two sub-no…

/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ static int wing=[]() { std::ios::sync_with_stdio(false); cin.tie(NULL); ; }();…

给定一个非空特殊的二叉树,每个节点都是正数,并且每个节点的子节点数量只能为 2 或 0.如果一个节点有两个子节点的话,那么这个节点的值不大于它的子节点的值. 给出这样的一个二叉树,你需要输出所有节点中的第二小的值.如果第二小的值不存在的话,输出 -1 . 题目应该少说了树的节点值都是大于等于0的 class Solution { public: int findSecondMinimumValue(TreeNode* root) { if(root == NULL) return -1; int…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 DFS BFS 日期 题目地址:https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree/ 题目描述 Given a binary tree, return the vertical order traversal of its nodes values. For…

[LeetCode]863. All Nodes Distance K in Binary Tree 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/all-nodes-distance-k-in-binary-tree/description/ 题目描述: We are given a binary tree (with root no…

[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…

Minimum Depth of Binary Tree Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. BFS碰到一个叶子结点就可以了. class Solution { public: int minDepth(TreeNo…

题目来源 https://leetcode.com/problems/validate-binary-search-tree/ Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node'…

1.  Path Sum 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…

Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node. 题解:递归,树的高度 = max(左子树高度,右子树高度)+1: 代码如下: /** * Definition for binary tree * public class Tre…

103. 二叉树的锯齿形层次遍历 103. Binary Tree Zigzag Level Order Traversal 题目描述 给定一个二叉树,返回其节点值的锯齿形层次遍历.(即先从左往右,再从右往左进行下一层遍历,以此类推,层与层之间交替进行). LeetCode103. Binary Tree Zigzag Level Order Traversal中等 例如: 给定二叉树 [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 返回锯齿形层次遍历如…

236. Lowest Common Ancestor of a Binary Tree Medium https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/ Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA o…

这是悦乐书的第374次更新,第401篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第235题(顺位题号是993).在二叉树中,根节点在深度0处,并且每个深度为k的节点的子节点,他们深度为k + 1. 如果二元树的两个节点具有相同的深度但具有不同的父节点,则它们是堂兄弟. 我们给出了具有唯一值的二叉树root,以及树中两个不同节点的值x和y. 当且仅当对应于值x和y的节点是堂兄弟时,才返回true.例如: 输入:root = [1,2,3,4],x = 4,y = 3…