Given a non-empty binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path must contain at least one node and doe…
题意:给一棵二叉树,要求找出任意两个节点(也可以只是一个点)的最大路径和,至少1个节点,返回路径和.(点权有负的.) 思路:DFS解决,返回值是,经过从某后代节点上来到当前节点且路径和最大的值.要注意如果子树传来的如果是负值,是可以同时丢弃的,但至少要将当前节点的val更新答案. /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right;…
题目: Given a non-empty binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path must contain at least one node and…
Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return 6. 题目意思很简单,就是给定一棵二叉树,求最大路径和.path 可以从任意 node 开始,到任意 node 结束. 这道题在 LeetCode 上的通过率只有 20% 多一点,并被…
题目: Binary Tree Maximum Path Sum Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return 6. 节点可能为负数,寻找一条最路径使得所经过节点和最大.路径可以开始和结束于任何节点但是不能走回头路. 这道题虽然看…
124. Binary Tree Maximum Path Sum https://www.cnblogs.com/grandyang/p/4280120.html 如果你要计算加上当前节点的最大path和,这个节点的左右子树必定是纯左右树(即没有拐点), 用另一个参数保留整个二叉树的最大path和,然后计算每一个以当前节点为拐点的路径和并且不断更新整个二叉树的最大值 函数的返回值是纯左右子树的最大path,没有拐点 这个题目给root定位为非空,所以直接这样写可以.如果root为空,这样写就会…
Binary Tree Maximum Path Sum Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example: Given the below binary tree, 1 / \ 2 3 Return 6. 递归求解. maxPathSum(root)跟maxPathSum(root.left)和maxPathSum(roo…
Binary Tree Maximum Path SumGiven a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1      / \     2   3 SOLUTION 1: 计算树的最长path有2种情况: 1. 通过根的path. (1)如果左子树从左树根到任何一个N…
124. Binary Tree Maximum Path Sum 题意:给定一个二叉树,每个节点有一个权值,寻找任意一个路径,使得权值和最大,只需返回权值和. 思路:对于每一个节点 首先考虑以这个节点为结尾(包含它或者不包含)的最大值,有两种情况,分别来自左儿子和右儿子设为Vnow. 然后考虑经过这个节点的情况来更新最终答案.更新答案后返回Vnow供父节点继续更新. 代码很简单. 有一个类似的很有趣的题目,给定一个二叉树,选择一条路径,使得权值最大的和最小的相差最大.参考POJ3728 cla…
Binary Tree Maximum Path Sum Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return 6.   用递归确定每一个节点作为root时,从root出发的最长的路径 在每一次递归中计算maxPath   /** * D…
Binary Tree Maximum Path Sum Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example: Given the below binary tree, 1 / \ 2 3 Return 6. 思想: 后序遍历.注意路径的连通: 结点不为空时要返回  max( max(leftV, rightV)+rootV,…
Binary Tree Maximum Path Sum Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return 6. 树结构显然用递归来解,解题关键: 1.对于每一层递归,只有包含此层树根节点的值才可以返回到上层.否则路径将不连续. 2.…
Given a binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path does not need to go through the root. For exampl…
Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return 6. 这道求二叉树的最大路径和是一道蛮有难度的题,难就难在起始位置和结束位置可以为任意位置,我当然是又不会了,于是上网看看大神们的解法,看了很多人的都没太看明白,最后发现了网友Yu's…
Given a non-empty binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path must contain at least one node and doe…
Level:   Hard 题目描述: Given a non-empty binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path must contain at le…
Given a non-empty binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path must contain at least one node and doe…
Given a binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path does not need to go through the root. For exampl…
Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return6. 思路:题目中说明起始节点可以是任意节点,所以,最大的路径和不一样要经过root,可以是左子树中某一条,或者是右子树中某一条,当然也可能是经过树的根节点root的.递归式是应该是这三…
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 给定一个二叉树,寻找值最大的路径. 这个路径可以从这个树上面的任意一个节点开始,然后在任意一个节点结束. 例如: 给定下面的二叉树, 1 / \ 2 3 返回 6. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ G…
Given a binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path does not need to go through the root. For exampl…
Given a binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path does not need to go through the root. For exampl…
原题地址:https://oj.leetcode.com/problems/binary-tree-maximum-path-sum/ 题意: Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return 6. 解题思路:这道题是在树中寻找一条路…
题目 Given a binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path does not need to go through the root. For exa…
Given a binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path does not need to go through the root. For exampl…
Given a binary tree, find the maximum path sum from root. The path may end at any node in the tree and contain at least one node in it. 给一棵二叉树,找出从根节点出发的路径中,和最大的一条. 这条路径可以在任何二叉树中的节点结束,但是必须包含至少一个点(也就是根了). /** * Definition of TreeNode: * public class Tr…
Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. 找树的最大路径和 注意路径可以从任意点起始和结束. 我发现我真的还挺擅长树的题目的,递归不难.就是因为有个需要比较的量(最大和),所以需要再写一个函数. 因为路径可以从任意点起始和结束,所以每次递归的时候左右子树小于等于0的就可以不管了. #include <iostream> #include…
Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3 Return 6. 算法:(有点动态规划的思想)首先明确要自底向上进行计算,只考虑当前节点root,我们从子节点向上返回的是一条线路目前的最大值,该线路最高层(最上面)的节点是该子节点,并且该子节点…
Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. For example:Given the below binary tree, 1 / \ 2 3   Return 6. 对于树,我们可以找到其左右子树中终止于根节点的最大路径值,称为最大半路径值,如果都是正数,则可以把它们以及根节点值相加,如果其中有负数,则舍弃那一边的值(即置为零).如此可以…
Given a binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path does not need to go through the root. For exampl…