给定一个二叉树,找到最长的路径,这个路径中的每个节点具有相同值. 这条路径可以经过也可以不经过根节点. 注意:两个节点之间的路径长度由它们之间的边数表示. 示例 1: 输入: 5 / \ 4 5 / \ \ 1 1 5 输出: 2 示例 2: 输入: 1 / \ 4 5 / \ \ 4 4 5 输出: 2 注意: 给定的二叉树不超过10000个结点. 树的高度不超过1000. struct TreeNode { int val; struct TreeNode *left; struct Tre…

Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may not pass through the root. Note: The length of path between two nodes is represented by the number of edges between them. Ex…

题目: Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may not pass through the root. The length of path between two nodes is represented by the number of edges between them. Exam…

Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may not pass through the root. Note: The length of path between two nodes is represented by the number of edges between them. Ex…

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 日期 题目地址:https://leetcode.com/problems/longest-univalue-path/description/ 题目描述 Given a binary tree, find the length of the longest path where each node in the path has the s…

problem 687. Longest Univalue Path 参考 1. Leetcode_easy_687. Longest Univalue Path; 2. Grandyang; 完…

Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may not pass through the root. Note: The length of path between two nodes is represented by the number of edges between them. Ex…

687. 最长同值路径 给定一个二叉树,找到最长的路径,这个路径中的每个节点具有相同值. 这条路径可以经过也可以不经过根节点. 注意:两个节点之间的路径长度由它们之间的边数表示. 示例 1: 输入: 5 / \ 4 5 / \ \ 1 1 5 输出: 2 示例 2: 输入: 1 / \ 4 5 / \ \ 4 4 5 输出: 2 注意: 给定的二叉树不超过10000个结点. 树的高度不超过1000. /** * Definition for a binary tree node. * publi…

总述 这类题目都是求一个最长路径,这个路径可以不经过根节点. 使用dfs(即递归地遍历树)的方法.维护一个全局最长路径max作为最终结果,而递归方法dfs返回的是含根节点的最长路径.(若不使用全局变量,也可将返回类型构造自定义类,如题目124的代码2) 注意题目是求路径(两点之间一条线)与节点数的区别, 决定+1之类的细节 决定dfs的递归终止是null节点还是叶子结点(若是叶子结点,当到叶子结点,要控制不进入null结点). 另外,求不经过根节点的最长路径一定是全部节点都要遍历,不存在剪枝情况…

这是悦乐书的第290次更新,第308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158题(顺位题号是687).给定二叉树,找到路径中每个节点具有相同值的最长路径的长度.此路径可能会也可能不会通过根目录.例如: 输入: 5 / \ 4 5 / \ \ 1 1 5 输出:路径为[5,5,5],边长为2 输入: 1 / \ 4 5 / \ \ 4 4 5 输出:路径为[4,4,4],边长为2 注意: 两个节点之间的路径长度由它们之间的边数表示. 给定的二叉树不超过10…

给定一个二叉树,找到最长的路径,这个路径中的每个节点具有相同值. 这条路径可以经过也可以不经过根节点. 注意:两个节点之间的路径长度由它们之间的边数表示. 示例 1: 输入: 5 / \ 4 5 / \ \ 1 1 5 输出: 2 示例 2: 输入: 1 / \ 4 5 / \ \ 4 4 5 输出: 2 注意: 给定的二叉树不超过10000个结点. 树的高度不超过1000. 思路:我们可以通过树结构发现,我们的每一个不同的同值路径(例如同值为2,或者同值为3),他们之间都是互不影响的,每次从一…

Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may not pass through the root. Note: The length of path between two nodes is represented by the number of edges between them. Ex…

［抄题］: Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may not pass through the root. Note: The length of path between two nodes is represented by the number of edges between th…

题目描述:给定一个二叉树,找到最长的路径,这个路径中的每个节点具有相同值.这条路径可以经过也可以不经过根节点.注意:两个节点之间的路径长度由它们之间的边数表示. 示例1:输入: 5 / \ 4 5 / \ \ 1 1 5输出:2 示例 2:输入: 1 / \ 4 5 / \ \ 4 4 5输出:2注意: 给定的二叉树不超过10000个结点.树的高度不超过1000. 先解释一下题目,就是让我们找到一个路径,这个路径上面的值都相同,而且可以不经过根节点,例如,例2中的4-4-4这样的. 刚做这道题的…

Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may not pass through the root. Note: The length of path between two nodes is represented by the number of edges between them. Ex…

寻找最长的路径,那么会在左边或者右边或者是从左到跟然后再到右方的路径的. /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: int longestUniva…

/** * 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); ; }();…

You are given a binary tree in which each node contains an integer value. Find the number of paths that sum to a given value. The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to…

Given an integer matrix, find the length of the longest increasing path. From each cell, you can either move to four directions: left, right, up or down. You may NOT move diagonally or move outside of the boundary (i.e. wrap-around is not allowed). E…

Leetcode之深度优先搜索(DFS)专题-329. 矩阵中的最长递增路径(Longest Increasing Path in a Matrix) 深度优先搜索的解题详细介绍,点击 给定一个整数矩阵,找出最长递增路径的长度. 对于每个单元格,你可以往上,下,左,右四个方向移动. 你不能在对角线方向上移动或移动到边界外(即不允许环绕). 示例 1: 输入: nums = [ [9,9,4], [6,6,8], [2,1,1] ] 输出: 4 解释: 最长递增路径为 [1, 2, 6, 9].…

Suppose we abstract our file system by a string in the following manner: The string "dir\n\tsubdir1\n\tsubdir2\n\t\tfile.ext" represents: dir subdir1 subdir2 file.ext The directory dir contains an empty sub-directory subdir1 and a sub-directory …

Given an integer matrix, find the length of the longest increasing path. From each cell, you can either move to four directions: left, right, up or down. You may NOT move diagonally or move outside of the boundary (i.e. wrap-around is not allowed). E…

Given an integer matrix, find the length of the longest increasing path.From each cell, you can either move to four directions: left, right, up or down. You may NOT move diagonally or move outside of the boundary (i.e. wrap-around is not allowed).Exa…

Suppose we abstract our file system by a string in the following manner: The string "dir\n\tsubdir1\n\tsubdir2\n\t\tfile.ext" represents: dir subdir1 subdir2 file.ext The directory dir contains an empty sub-directory subdir1 and a sub-directory …

2018-07-30 22:05:52 问题描述: 问题求解: 本题个人感觉还是挺有意思的,题目要求的是最长的文件路径,其实是需要keep tracking路径长度,如果出现文件则需要进行比较,看是否为当前的最大长度. 难点就在于如何keep tracking,不妨将文件的路径旋转90度,那么就可以看到很明显的层次结构,我们可以使用一个栈来维护不同层次的信息,想到这里本题其实基本已经解决了一大半,剩下的就是层次关系的判断,显然和\t有关,那么对这个再进行分析,就很快可以得到解. 这里需要注意的是…

Given an integer matrix, find the length of the longest increasing path. From each cell, you can either move to four directions: left, right, up or down. You may NOT move diagonally or move outside of the boundary (i.e. wrap-around is not allowed). E…

Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may not pass through the root. Note: The length of path between two nodes is represented by the number of edges between them. Ex…

Given an integer matrix, find the length of the longest increasing path. From each cell, you can either move to four directions: left, right, up or down. You may NOT move diagonally or move outside of the boundary (i.e. wrap-around is not allowed). E…

题目 Given an integer matrix, find the length of the longest increasing path. From each cell, you can either move to four directions: left, right, up or down. You may NOT move diagonally or move outside of the boundary (i.e. wrap-around is not allowed)…

作者:jostree 转载请注明出处 http://www.cnblogs.com/jostree/p/4098562.html 题目链接:poj 2533 Longest Ordered Subsequence 最长递增子序列 使用$len[i]$表示序列中所有长度为$i$的递增子序列中最小的第$i$个数的值为$len[i]$.对于序列的第j个数$arr[j]$,在$len$中二分查找,找到最后一个小于$arr[j]$的数$len[k]$,如果$len[k]$是序列$len$中最后的一个数,那…