给你一个二叉树,问安装多少摄像头,可以监控到所有节点。摄像头监控范围为父母孩子和自己。 二. 思路 三个数字表示三种状态: 用数字1表示有摄像头; 数字0表示需要安装摄像头; 数字2表示不需要安装摄像头。 代码: class Solution { int res = 0; public int minCameraCover(TreeNode root) { return (dfs(root...
二叉树放置照相机 Binary Tree Cameras 2019-03-27 15:39:37 问题描述: 问题求解: 很有意思的问题,问题描述简单,求解过程也可以非常的简洁,是个难得的好题。 求解的过程是自底向上进行分析,对于叶子节点,如果在叶子上放置照相机,显然是没有在其parent上放置相机来的合适的,因为叶子节点的覆盖范围没有其parent节...
classSolution:defminCameraCover(self,root:TreeNode)->int:self.ans=0defbottomup(cur):ifnotcur:return1left,right=bottomup(cur.left),bottomup(cur.right)ifleft==0orright==0:self.ans+=1return2elifleft==1andright==1:return0else:return1ifbottomup(root)==0:self.ans+=1returnself.ans...
Given a binary tree, we install cameras on the nodes of the tree. Each camera at a node can monitor its parent, itself, and its immediate children. Calculate the minimum number of cameras needed to monitor all nodes of the tree. Example 1: Input:[0,0,null,0,0]Output:1Explanation:One...
968. Binary Tree Cameras 监控二叉树 给定一个二叉树,我们在树的节点上安装摄像头。 节点上的每个摄影头都可以监视其父对象、自身及其直接子对象。 计算监控树的所有节点所需的最小摄像头数量。 示例1: 输入:[0,0,null,0,0]输出:1解释:如图所示,一台摄像头足以监控所有节点。
Explanation: At least two cameras are needed to monitor all nodes of the tree. The above image shows one of the valid configurations of camera placement. 1. 2. 3. Constraints: The number of nodes in the tree is in the range[1, 1000]. ...
0958-Check-Completeness-of-a-Binary-Tree 0959-Regions-Cut-By-Slashes 0960-Delete-Columns-to-Make-Sorted-III 0961-N-Repeated-Element-in-Size-2N-Array 0965-Univalued-Binary-Tree 0966-Vowel-Spellchecker 0967-Numbers-With-Same-Consecutive-Differences 0968-Binary-Tree-Cameras/cpp...
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Species, clusters and the 'Tree of life':A graph-theoretic perspective A hierarchical structure describing the inter-relationships of species has long been a fundamental concept in systematic biology, from Linnean classificati... Dress,A,Moulton,... - 《Journal of Theoretical Biology》 被引量: ...
Binary Tree Cameras (H) 题目 Given a binary tree, we install cameras on the nodes of the tree. Each camera at a node can monitorits parent, itself, and its immediate children. Calculate the minimum number of cameras needed to monitor all nodes of the tree. ...