structTreeNode{set<int> list;//使用set结构方便删除邻居TreeNode(){};boolisLeaf(){returnlist.size()==1;};//这边的分号不能丢};//这个分号也不能丢vector<int> findMinHeightTrees(intn, vector<pair<int,int>>&edges) {if(n==1)return{0};//使用节点来存储这棵树,耗费的空间为O(n+2e)vector...
将当前节点以及其中一个相邻节点组合分支方向,求得该分支高度后存入 map<string, int> direc_height 中,其中 direc 有这两个节点组成作为 key ,height 表示高度。 若不使用表格优化,时间复杂度为 O(V*E)。使用表格,相当于进行了剪枝,会快不少。跑 LeetCode 的大集合 V = 1000, E =2000 ,测试耗时是 820...
publicList<Integer>findMinHeightTrees(intn,int[][]edges){List<Integer>res=newArrayList<>();if(n==1){res.add(0);returnres;}//图的存储邻接表List<List<Integer>>g=newArrayList<>();for(inti=0;i<n;i++){g.add(newArrayList<>());}int[]indegree=newint[n];for(int[]edge:edges){intu...
those with minimum height are called minimum height trees (MHTs). Given such a graph, write a function to find all the MHTs and return a list of their root labels.
链接:https://leetcode-cn.com/problems/minimum-height-trees 思路: 首先用bfs或者dfs求树高度是很好求的,但是将每一个节点尝试做根节点,每个都求一边复杂度较高,据说会超时。 因此,这个题目采用的是一个比较灵活的BFS方法,即从叶子节点开始BFS,像剥洋葱一样先把最外层的度数为1的叶子节点剥去,获得一个新的树...
For an undirected graph with tree characteristics, we can choose any node as the root. The result graph is then a rooted tree. Among all possible rooted trees, those with minimum height are called minimum height trees (MHTs). Given such a graph, write a function to find all the MHTs ...
LeetCode 310. Minimum Height Trees 简介:对于一个具有树特征的无向图,我们可选择任何一个节点作为根。图因此可以成为树,在所有可能的树中,具有最小高度的树被称为最小高度树。给出这样的一个图,写出一个函数找到所有的最小高度树并返回他们的根节点。
Leetcode 310. Minimum Height Trees 题目: For a undirected graph with tree characteristics, we can choose any node as the root. The result graph is then a rooted tree. Among all possible rooted trees, those with minimum height are called minimum height trees (MHTs). Given such a graph, ...
class Solution { public: vector<int> findMinHeightTrees(int n, vector<vector<int>>& edges) { } }; 已存储 行1,列 1 运行和提交代码需要登录 Case 1Case 2 n = 4 edges = [[1,0],[1,2],[1,3]] 1 2 3 4 4 [[1,0],[1,2],[1,3]] 6 [[3,0],[3,1],[3,2],[3,4],...
310. Minimum Height Trees https://leetcode.com/problems/minimum-height-trees/discuss/76055/Share-some-thoughtsFor a undirected graph with tree characteristics, we can choose any node as the root. The result graph is then a rooted tree. Among all possible rooted trees, those with minimum ...