yanguo110-CSDN博客

原创 JDK1.8的一些特性

前言对于jdk1.8的特性之前没有很好地的了解过，现在花一些时间整理一下。只摘取频率使用较高的方法进行介绍。一、分组将id一样的苹果放在一起Map<Integer, List<Apple>> collect = apples.stream().collect(Collectors.groupingBy(Apple::getId)); System.out.println("分组-res：" + collect);二、Lis转成mapCollectors.toMa

2020-09-07 22:21:15 269

原创 Rabbitmq系列之整合Haproxy实现负载均衡

概述 HAProxy 提供高可用性、负载均衡及基于 TCP 和 HTTP 应用的代理，支持虚拟主机，它是免费、快速并且可靠的一种解决方案，包括 Twitter、Reddit、StackOverflow、GitHub 在内的多家知名互联网公司在使用。 HAProxy 实现了一种事件驱动、单一进程模型，此模型支持非常大的井发连接数。摘自《RabbitMQ实战指南》安装使用阿里云的镜像wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliy

2020-08-16 17:14:46 337

原创 Rabbitmq系列之镜像模式部署

相关概念 RabbitMQ集群里有内存节点与磁盘节点。内存节点(ram)，就是将元数据（metadata）都放在内存里，磁盘节点(disc)，数据放在磁盘上，如果RabbitMQ是单节点运行，默认就是磁盘节点。在RabbitMQ集群里，至少有一个磁盘节点，它用来持久保存元数据。新的节点加入集群后，会从磁盘节点上拷贝数据。但是，集群里也不必要每个节点都是磁盘节点，这主要是性能问题。例如，压力大的RPC服务，每秒都要创建和销毁数百个队列，如果集群里都是磁盘节点，意味着队列定义在每个节点上，都要

2020-08-05 00:27:53 721

原创 Rabbitmq系列之普通集群部署

文章目录一、为什么要使用集群？二、什么是Rabbitmq集群？2.1、单一模式2.2、普通模式：2.3、镜像模式三、怎么使用Rabbitmq集群？3.1、首先iu'l'na一、为什么要使用集群？集群是为了解决单机可能出现宕机等引发的不可用的问题，可以有效提高程序的可用性和可靠性以及抗并发的能力。二、什么是Rabbitmq集群？2.1、单一模式即单机情况不做集群，就单独运行一个rabbitmq而已。2.2、普通模式：默认模式，以两个节点（rabbit01、rabbit02）为例来进行

2020-08-02 17:38:29 617

原创 Rabbitmq三个节点不能同时启动的问题，即有一个节点启动失败

文章目录一、为什么要使用集群？二、什么是Rabbitmq集群？2.1、单一模式2.2、普通模式：2.3、镜像模式三、怎么使用Rabbitmq集群？3.1、集群的形成的条件一、为什么要使用集群？集群是为了解决单机可能出现宕机等引发的不可用的问题，可以有效提高程序的可用性和可靠性以及抗并发的能力。二、什么是Rabbitmq集群？2.1、单一模式即单机情况不做集群，就单独运行一个rabbitmq而已。2.2、普通模式：默认模式，以两个节点（rabbit01、rabbit02）为例来进行说

2020-07-28 23:04:00 1086

原创 Rabbitmq单机版搭建

一、题外话安装之前先大致浏览一下Rabbitmq官网,如果有一天本文也老去，请以官网为准。在安装时需要注意Erlang环境和Rabbitmq版本是否兼容。二、安装配置erlang环境 1.1 安装rabbitmq需要考虑与之兼容的erlang版本,详情点击这里。 1.2 安装Erlang版本，有两种选择 PackageCloud仓库和 Bintray仓库，这里我选择Bintray仓库的配置。而且我的版本是 CentOS 7，如果是其他版本可以点击这里找适合的版本。vim /e

2020-07-26 11:18:15 868

原创 50-Remove Covered Intervals

题目地址：Remove Covered Intervals。Given a list of intervals, remove all intervals that are covered by another interval in the list. Interval [a,b) is covered by interval [c,d) if and only if c <= a a...

2020-03-11 11:35:40 194

原创 49-Generate Random Point in a Circle

题目地址：Generate Random Point in a CircleGiven the radius and x-y positions of the center of a circle, write a function randPoint which generates a uniform random point in the circle.Note:input and o...

2020-03-05 16:12:08 163

原创 48-Longest Increasing Path in a Matrix

题目地址：Longest Increasing Path in a MatrixGiven an integer matrix, find the length of the longest increasing path.From each cell, you can either move to four directions: left, right, up or down. You ...

2020-03-05 10:10:39 156

原创 47-Course Schedule II

题目地址：Course Schedule IIThere are a total of n courses you have to take, labeled from 0 to n-1.Some courses may have prerequisites, for example to take course 0 you have to first take course 1, whic...

2020-03-03 17:21:34 120

原创 46-Course Schedule

题目地址：Course ScheduleThere are a total of n courses you have to take, labeled from 0 to n-1.Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which i...

2020-03-02 18:26:54 101

原创 45-Binary Search Tree to Greater Sum Tree

题目地址：Binary Search Tree to Greater Sum TreeGiven the root of a binary search tree with distinct values, modify it so that every node has a new value equal to the sum of the values of the original tr...

2020-02-27 15:57:37 96

原创 44-Implement Rand10() Using Rand7()

题目地址：Implement Rand10() Using Rand7()Given a function rand7 which generates a uniform random integer in the range 1 to 7, write a function rand10 which generates a uniform random integer in the rang...

2020-02-25 18:18:20 62

原创 43-Linked List Random Node

题目地址：Linked List Random NodeGiven a singly linked list, return a random node’s value from the linked list. Each node must have the same probability of being chosen.Follow up:What if the linked lis...

2020-02-25 13:47:28 159

原创 42- Subsets

题目地址：SubsetsGiven a set of distinct integers, nums, return all possible subsets (the power set).Note: The solution set must not contain duplicate subsets.Example:Input: nums = [1,2,3]Output:[[...

2020-01-04 15:59:36 88

原创 41- Combinations

题目地址：CombinationsGiven two integers n and k, return all possible combinations of k numbers out of 1 … n.Example:Input: n = 4, k = 2Output:[[2,4],[3,4],[2,3],[1,2],[1,3],[1,4],]class Sol...

2019-12-30 16:10:16 85

原创 40-Permutation Sequence

题目地址：Permutation SequenceThe set [1,2,3,…,n] contains a total of n! unique permutations.By listing and labeling all of the permutations in order, we get the following sequence for n = 3:“123”“132...

2019-12-22 10:57:38 85

原创三天一题-39-Sort Colors

题目地址：Sort ColorsGiven an array with n objects colored red, white or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white and blue.Here, w...

2019-12-14 17:26:49 87

原创三天一题-38-Merge Intervals

题目地址：Jump GameGiven an array of non-negative integers, you are initially positioned at the first index of the array.Each element in the array represents your maximum jump length at that position.D...

2019-12-04 10:40:50 90

原创三天一题-37-Jump Game

2019-11-27 21:49:48 78

原创三天一题-36-Spiral Matrix

题目地址：Spiral MatrixGiven a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.Example 1:Input:[[ 1, 2, 3 ],[ 4, 5, 6 ],[ 7, 8, 9 ]]Output: [1,2,3,...

2019-11-24 16:13:21 98

原创三天一题-35-字母异位词分组

题目地址：字母异位词分组给定一个字符串数组，将字母异位词组合在一起。字母异位词指字母相同，但排列不同的字符串。示例:输入: [“eat”, “tea”, “tan”, “ate”, “nat”, “bat”],输出:[[“ate”,“eat”,“tea”],[“nat”,“tan”],[“bat”]]说明：所有输入均为小写字母。不考虑答案输出的顺序。来源：力扣（Lee...

2019-11-19 14:22:02 109

原创三天一题-34- Rotate Image

题目地址： Rotate Image描述：You are given an n x n 2D matrix representing an image.Rotate the image by 90 degrees (clockwise).Note:You have to rotate the image in-place, which means you have to modify...

2019-11-13 10:07:39 102

原创三天一题-33-Combination SumII（回溯思想）

题目地址： Combination Sum II描述：Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target....

2019-11-02 17:22:24 100

原创三天一题-32-Combination Sum（回溯思想）

题目地址： Combination Sum描述：Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums ...

2019-10-28 10:02:40 109

原创三天一题-31-Valid Sudoku

题目地址： Valid Sudoku描述：Determine if a 9x9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:Each row must contain the digits 1-9 without repetition.E...

2019-10-21 10:24:30 91

原创三天一题-30-Find First and Last Position of Element in Sorted Array

题目地址：Find First and Last Position of Element in Sorted Array描述：Given an array of integers nums sorted in ascending order, find the starting and ending position of a given target value.Your algorith...

2019-10-17 14:02:06 92

原创三天一题-29-Search in Rotated Sorted Array

题目地址：Search in Rotated Sorted Array描述：Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.(i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]).You are gi...

2019-10-14 15:19:17 102

原创三天一题-28-Next Permutation

题目地址：Next Permutation描述：Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.If such arrangement is not possible, it must rearrange i...

2019-10-10 15:06:12 80

原创三天一题-27-两数相除

题目地址：两数相除描述：给定两个整数，被除数 dividend 和除数 divisor。将两数相除，要求不使用乘法、除法和 mod 运算符。返回被除数 dividend 除以除数 divisor 得到的商。示例 1:输入: dividend = 10, divisor = 3输出: 3示例 2:输入: dividend = 7, divisor = -3输出: -2说明:被...

2019-09-24 14:20:56 126

原创三天一题-26-两两交换链表中的节点

题目地址：Swap Nodes in Pairs描述：Given a linked list, swap every two adjacent nodes and return its head.You may not modify the values in the list’s nodes, only nodes itself may be changed.Example:Give...

2019-09-21 09:35:16 76

原创三天一题-25-Generate Parentheses

题目地址：Generate Parentheses描述：Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.For example, given n = 3, a solution set is:[“((()))”,“(()())”...

2019-09-15 21:44:35 85

原创三天一题-24-删除链表倒数第n个元素

题目地址：Remove Nth Node From End of List描述：Given a linked list, remove the n-th node from the end of list and return its head.Example:Given linked list: 1->2->3->4->5, and n = 2.After r...

2019-09-10 14:33:43 86

原创三天一题-23- 4Sum

题目地址：4Sum描述：Given an array nums of n integers and an integer target, are there elements a, b, c, and d in nums such that a + b + c + d = target? Find all unique quadruplets in the array which gives...

2019-09-03 22:20:10 95

原创三天一题-23- 通过数字串读取对应的字母组合

题目地址：letteCombinationsPhoneNumberimport java.util.ArrayList;import java.util.HashMap;import java.util.LinkedList;import java.util.List;public class LetterCombinations { public static void ...

2019-08-30 09:05:45 156

原创三天一题-22- 3Sum（最接近目标值的三数之和）

题目地址：3Sum Closest描述：Given an array nums of n integers and an integer target, find three integers in nums such that the sum is closest to target. Return the sum of the three integers. You may assu...

2019-08-18 17:33:55 90

原创三天一题-21- 3Sum（三数加起来等于0）

题目地址：3Sum描述：Given an array nums of n integers, are there elements a, b, c in nums such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero–摘自《领扣》Example 2:Giv...

2019-08-14 23:19:16 106

原创三天一题-20- Integer to Roman（Integer转成古罗马数字）

题目原地址：Integer to Roman描述：For example, two is written as II in Roman numeral, just two one’s added together. Twelve is written as, XII, which is simply X + II. The number twenty seven is written a...

2019-08-11 14:30:45 99

原创三天一题-19- Container With Most Water（盛最多水的容器）

题目原地址：Container With Most Water描述：给定 n 个非负整数 a1，a2，…，an，每个数代表坐标中的一个点 (i, ai) 。在坐标内画 n 条垂直线，垂直线 i 的两个端点分别为 (i, ai) 和 (i, 0)。找出其中的两条线，使得它们与 x 轴共同构成的容器可以容纳最多的水。说明：你不能倾斜容器，且 n 的值至少为 2。–摘自《领扣》图中垂...

2019-08-07 13:00:09 103

原创三天一题-18- 字符串转换整数 (atoi)

题目地址：字符串转换整数 (atoi)描述：给定一个字符串，依次读取，当首个非空字符为“-”或者数字的时候，进行读取连续的数字；当数字大于Integer最大值时返回最大值；当数字小于最小值时返回最小值；否则返回0；Example 1:输入: " -42"输出: "-42"Example 2:输入: "4193 with words"输出: 4193Example 3:输...

2019-08-03 18:17:42 149