5355. T 秒后青蛙的位置 给你一棵由 n 个顶点组成的无向树,顶点编号从 1 到 n.青蛙从 顶点 1 开始起跳.规则如下: 在一秒内,青蛙从它所在的当前顶点跳到另一个 未访问 过的顶点(如果它们直接相连). 青蛙无法跳回已经访问过的顶点. 如果青蛙可以跳到多个不同顶点,那么它跳到其中任意一个顶点上的机率都相同. 如果青蛙不能跳到任何未访问过的顶点上,那么它每次跳跃都会停留在原地. 无向树的边用数组 edges 描述,其中 edges[i] = [fromi, toi] 意味着存在一条直接…
145. 二叉树的后序遍历 给定一个二叉树,返回它的 后序 遍历. 示例: 输入: [1,null,2,3] 1 \ 2 / 3 输出: [3,2,1] 进阶: 递归算法很简单,你可以通过迭代算法完成吗? /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * }…
Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. Find and return the shortest palindrome you can find by performing this transformation. For example: Given "aacecaaa", return "aaacecaaa&qu…
Given a set of non-overlapping intervals, insert a new interval into the intervals (merge if necessary). You may assume that the intervals were initially sorted according to their start times. Example 1: Given intervals [1,3],[6,9], insert and merge…
Given a collection of numbers that might contain duplicates, return all possible unique permutations. For example, [1,1,2] have the following unique permutations: [1,1,2], [1,2,1], and [2,1,1]. 解题思路一: 发现Java for LeetCode 046 Permutations自己想多了,代码直接拿来用…
启动之后发现slave上正常启动了DataNode,DataManager,但是过了几秒后发现DataNode被关闭 以slave1上错误日期为例查看错误信息: /logs/hadoop-spark-datanode-slave1.log 找到错误信息: -- ::, WARN org.apache.hadoop.hdfs.server.common.Storage: Failed to add storage directory [DISK]/dfs/data/ java.io.IOExcep…
LeetCode:二叉树的后序遍历[145] 题目描述 给定一个二叉树,返回它的 后序 遍历. 示例: 输入: [1,null,2,3] 1 \ 2 / 3 输出: [3,2,1] 进阶: 递归算法很简单,你可以通过迭代算法完成吗? 题目分析 这道题难度和N叉树的后序遍历是等同的,但是标注为困难. 首先我们都知道,栈顶元素一般都是根元素,弹出根元素,加入根元素的左节点.右节点后,位于栈顶的是根元素的最右子节点,栈低的是根元素的最左子节点. 如果我们按照这个顺序打印的话,输出的是[1,2,3].如…
5秒钟后自动关闭 <!DOCTYPE HTML> <html> <head> <title>倒计时自动关闭/跳转页面</title> <meta charset="utf-8" /> <script> //定义函数myClose关闭当前窗口 function myClose(){ //将id为time的元素的内容转为整数,保存在变量n中 var n=parseInt(time.innerHTML); n…
Given two words (start and end), and a dictionary, find all shortest transformation sequence(s) from start to end, such that: Only one letter can be changed at a time    Each intermediate word must exist in the dictionary For example, Given:start = "…
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