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

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.…

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…

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.…

［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…

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…

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…

/** * 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); ; }();…

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…

[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…

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 日期 题目地址:https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/description/ 题目描述 Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in…

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…

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.…

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.…

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…

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 on Wikipedia: “The lowest common ancestor is defined between two nodes v and w as th…

题目如下: Given a binary tree with the following rules: root.val == 0 If treeNode.val == x and treeNode.left != null, then treeNode.left.val == 2 * x + 1 If treeNode.val == x and treeNode.right != null, then treeNode.right.val == 2 * x + 2 Now the binary…

题目如下: Given the root of a binary tree, the level of its root is 1, the level of its children is 2, and so on. Return the smallest level X such that the sum of all the values of nodes at level X is maximal. Example 1: Input: [1,7,0,7,-8,null,null] Out…

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 / \ / \ / \ # # # # #…

题目如下: Given a binary tree, return the vertical order traversal of its nodes values. For each node at position (X, Y), its left and right children respectively will be at positions (X-1, Y-1)and (X+1, Y-1). Running a vertical line from X = -infinity t…

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 BFS 日期 题目地址:https://leetcode.com/problems/maximum-level-sum-of-a-binary-tree/ 题目描述 Given the root of a binary tree, the level of its root is 1, the level of its children is 2, a…

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…

problem 1022. Sum of Root To Leaf Binary Numbers 参考 1. Leetcode_easy_1022. Sum of Root To Leaf Binary Numbers; 完…

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…

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…

[agc030f]Permutation and Minimum(动态规划) 题面 atcoder 给定一个长度为\(2n\)的残缺的排列\(A\),定义\(b_i=min\{A_{2i-1},A_{2i}\}\),求有多少种不同的\(b\). 题解 考虑这个\(b\)的取值是两两配对之后求\(min\),所以我们把所有的数按照从大往小处理,这样子就可以在每一对数填好的时候计算贡献. 首先把已经确定的\(b\)直接丢掉.这样子剩下了若干个填了一半和没有填的对. 设\(f[i][j][k]\)表示…

[LeetCode]153. Find Minimum in Rotated Sorted Array 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/description/ 题目描述: Suppose an array sorted in ascending order is rotated at some pivot unknown to yo…