An undirected, connected tree with N nodes labelled 0...N-1 and N-1 edges are given. The ith edge connects nodes edges[i][0] and edges[i][1] together. Return a list ans, where ans[i] is the sum of the distances between node i and all other nodes. Exa…

LeetCode刷题记录 传送门 Description An undirected, connected treewith N nodes labelled 0...N-1 and N-1 edges are given. The ith edge connects nodes edges[i][0] and edges[i][1] together. Return a list ans, where ans[i] is the sum of the distances between nod…

Sum of Distances in Tree An undirected, connected tree with N nodes labelled 0...N-1 and N-1 edges are given. The ith edge connects nodes edges[i][0] and edges[i][1] together. Return a list ans, where ans[i] is the sum of the distances between node i…

There is an undirected connected tree with n nodes labeled from 0 to n - 1 and n - 1 edges. You are given the integer n and the array edges where edges[i] = [ai, bi] indicates that there is an edge between nodes ai and bi in the tree. Return an array…

834. 树中距离之和 给定一个无向.连通的树.树中有 N 个标记为 0-N-1 的节点以及 N-1 条边 . 第 i 条边连接节点 edges[i][0] 和 edges[i][1] . 返回一个表示节点 i 与其他所有节点距离之和的列表 ans. 示例 1: 输入: N = 6, edges = [[0,1],[0,2],[2,3],[2,4],[2,5]] 输出: [8,12,6,10,10,10] 解释: 如下为给定的树的示意图: 0 / 1 2 /| 3 4 5 我们可以计算出 dis…

An undirected, connected tree with N nodes labelled 0...N-1 and N-1 edges are given. The ith edge connects nodes edges[i][0]and edges[i][1] together. Return a list ans, where ans[i] is the sum of the distances between node i and all other nodes. Exam…

2019-03-28 15:25:43 问题描述: 问题求解: 写过的最好的Hard题之一. 初看本题,很经典的路径和嘛,dfs一遍肯定可以得到某个节点到其他所有节点的距离和.这种算法的时间复杂度是O(n ^ 2).看一下数据量,emmm,果然不行.这个数据量一看就知道只能是O(n)的算法了. 只遍历一遍最多只能得到一个解,因此本题肯定是需要遍历至少两遍的. 在第一遍遍历的时候我们需要保存下两个值,一个是当前节点的subtree的路径总和,一个是当前节点的subtree的总的节点数. 在第二遍遍…

思路: 树形dp. 实现: class Solution { public: void dfs(int root, int p, vector<vector<int>>& G, vector<int>& cnt, vector<int>& res) { for (auto it: G[root]) { if (it == p) continue; dfs(it, root, G, cnt, res); cnt[root] += cnt…

Find the sum of all left leaves in a given binary tree. Example: 3 / \ 9 20 / \ 15 7 There are two left leaves in the binary tree, with values 9 and 15 respectively. Return 24. 题目标签:Tree 这道题目给了我们一个二叉树,让我们找到所有左子叶之和.这里需要另外一个function - sumLeftLeaves 还要一…

Design and implement a TwoSum class. It should support the following operations:add and find. add - Add the number to an internal data structure.find - Find if there exists any pair of numbers which sum is equal to the value. For example,add(1); add(…