classSolution{public:intmaxLevelSum(TreeNode* root){ vector<int> sums;helper(root,1, sums);returndistance(begin(sums),max_element(begin(sums),end(sums))) +1; }voidhelper(TreeNode* node,intlevel, vector<int>& sums){if(!node)return;if(sums.size() < level) sums.resize(level); sums[...
Given therootof a binary tree, the level of its root is1, the level of its children is2, and so on. Return the smallest levelXsuch that the sum of all the values of nodes at levelXis maximal. Example 1: Input:[1,7,0,7,-8,null,null] Output:2 Explanation: Level 1 sum = 1. ...
树状数组也叫二叉索引树(Binary Indexed Tree),是一种支持 “单点修改” 和 “区间查询” 的代码量少的数据结构。相比于线段树来说,树状数组的代码量远远更少,是一种精妙的数据结构。 树状数组核心思想是将数组 [0,x] 的前缀和拆分为不多于 logx 段非重叠的区间,在计算前缀和时只需要合并 logx 段区间信息,...
/** * Definition for a binary tree node. * function TreeNode(val) { * this.val = val; * this.left = this.right = null; * } */// the number of the paths starting from selffunction helper(root, sum) { if (root === null) return 0; const l = helper(root.left, su...
rangeSumBST(root.right, low, high) return ans 代码(Go) /** * Definition for a binary tree node. * type TreeNode struct { * Val int * Left *TreeNode * Right *TreeNode * } */ func rangeSumBST(root *TreeNode, low int, high int) int { // 如果 root 子树为空,则直接返回 0 ...
/* * @lc app=leetcode id=124 lang=javascript * * [124] Binary Tree Maximum Path Sum *//** * Definition for a binary tree node. * function TreeNode(val) { * this.val = val; * this.left = this.right = null; * } */function helper(node, payload) { if (node === n...
124. Binary Tree Maximum Path Sum 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 ...
Can you solve this real interview question? Maximum Sum BST in Binary Tree - Given a binary tree root, return the maximum sum of all keys of any sub-tree which is also a Binary Search Tree (BST). Assume a BST is defined as follows: * The left subtree
Given a binary tree, find the maximum path sum. The path may start and end at any node in the tree. Example Given the below binary tree: 1 / \ 2 3 return6. 题解1 - 递归中仅返回子树路径长度 如题目右侧的四颗半五角星所示,本题属于中等偏难的那一类题。题目很短,要求返回最大路径和。咋...
Can you solve this real interview question? Binary Search Tree to Greater Sum Tree - Given the root of a Binary Search Tree (BST), convert it to a Greater Tree such that every key of the original BST is changed to the original key plus the sum of all key