SYSU_BY-CSDN博客

原创 Linux下Mysql添加用户操作踩到的坑

最近，笔者正在做的project想要对数据库做比较多的调试，同时也为了方便开发与版本部署以及之后数据库的整体迁移，于是想在数据库添加用户操作以及开放数据库的远程访问，折腾了一个多小时，学到了以下一些内容。环境与目标操作系统： centos7.2数据库： MariaDB，MariaDB与mysql给用户的体验差别不大，基本都是兼容的，常用命令也基本相同。目标：原有登录数据库用root账户，...

2019-02-27 14:53:41 294

原创 Windows Server2008配置Django与数据库环境

前两天突然之间被指派了一个任务，需要几天之内在数据中心的实验室一台Windows Server2008服务器上面做一个网站来可视化显示传感器采集的数据。而传感器数据具有特定格式，并且从数据中心的动环系统中采集得到，由于动环系统的配置、数据的冗余存储等各方面问题，服务器的OS与数据库不能变化，因此只能在此基础上想办法适应开发。为了不影响服务器正常工作，笔者决定用虚拟机搭建起与服务器一模一样的环境开发...

2018-12-07 10:42:38 892

原创点云配准算法的综述

点云配准实际上可以理解为：通过计算得到完美的坐标变换，将处于不同视角下的点云数据经过**旋转平移等刚性变换**统一整合到指定坐标系之下的过程。再通俗一点讲：进行配准的两个点云，它们彼此之间可以通过旋转平移等这种位置变换完全重合，因此这两个点云属于刚性变换即形状大小是完全一样的，只是坐标位置不一样而已。点云配准就是求出两个点云之间的坐标位置变换关系。

2018-06-07 23:52:01 19147 14

原创树莓派设备端口号绑定

project做到最近，遇到了一个尴尬的问题：一台树莓派接了多个设备，例如多个arduino、串口转USB和无线键鼠等等。物理上USB不够，直接将一个USB hub就可以了。

2017-08-25 20:41:28 4787 1

原创一个利用CAN实现车辆控制的简单模板

CAN的全称是controller area network是一种车内常用的通信协议，网络的设备直接互联通信。基本上，现在很多车都是使用CAN协议作为车内ECU与各个模块之间的通信手段。

2017-07-19 16:32:32 1735 1

原创 LeetCode542. 01 Matrix题解

Given a matrix consists of 0 and 1, find the distance of the nearest 0 for each cell. The distance between two adjacent cells is 1.

2017-06-26 13:04:50 900

原创《算法概论》8.3

STINGY SET is the following problem: given a set of clauses (each a disjunction of literals) and an integer k, find a satisfying assignment in which at most k variables are true

2017-06-22 13:36:12 424

原创 Sicily1005. 最大和题解

从数列A[0], A[1], A[2], …, A[N-1]中选若干个数，要求相邻的数不能都选，也就是说如果选了A[i], 就不能选A[i-1]和A[i+1]. 求能选出的最大和. 1 <= N <= 100000, 1 <= A[i] <= 10002.

2017-06-18 13:50:49 442

原创 Sicily1209. Sequence Sum Possibi题解

题目描述Most positive integers may be written as a sum of a sequence of at least two consecutive positive integers.

2017-06-08 20:10:39 365 1

原创 Sicily1210.二叉树题解

题目描述在众多的数据结构中，二叉树是一种特殊而重要的结构，有着广泛的应用。二叉树或者是一个结点，或者有且仅有一个结点为二叉树的根，其余结点被分成两个互不相交的子集，一个作为左子集，另一个作为右子集，每个子集又是一个二叉树。

2017-06-07 19:28:16 748

原创利用树莓派搭建简易服务器

读研以来笔者一直负责实验室的网络维护，可以说是实验室名副其实的首席大网管。有一天笔者突发奇想，拿了手头的树莓派3结合主路由器搭建了一个稳定的服务器，效果还不错，把搭建方法和过程和大家分享一下。主要包括了git服务器，远程视频监控服务器和网页游戏服务器。

2017-06-07 00:04:24 21736

原创 LeetCode494. Target Sum题解

You are given a list of non-negative integers, a1, a2, …, an, and a target, S. Now you have 2 symbols + and -. For each integer, you should choose one from + and - as its new symbol.

2017-06-04 16:30:00 1881 4

原创密码学与网络安全笔记整理-伽罗华环

有限域具体来说是近世代数的内容，我们组要做presentation的内容是在此基础上，有关伽罗华环的定义和一些性质。

2017-06-02 00:52:28 2137

原创 LeetCode48. Rotate Image题解

You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). 题目很简单，给了一个n*n的2D方阵，我们需要将其顺时针旋转90°。

2017-06-01 16:26:41 547

原创 LeetCode486. Predict the Winner题解

Given an array of scores that are non-negative integers. Player 1 picks one of the numbers from either end of the array followed by the player 2 and then player 1 and so on.

2017-05-24 17:16:27 603

原创 LeetCode357. Count Numbers with Unique Digits题解

题目描述Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x < 10^(n).

2017-05-17 14:18:57 361

原创 LeetCode338. Counting Bits题解

Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1’s in their binary representation and return them as an array.

2017-05-10 22:19:05 318

原创 LeetCode70. Climbing Stairs题解

You are climbing a stair case. It takes n steps to reach to the top.Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?

2017-05-05 12:41:41 417

原创 LeetCode121. Best Time to Buy and Sell Stock题解

Say you have an array for which the i element is the price of a given stock on day i.If you were only permitted to complete at most one transaction.

2017-05-04 00:07:51 311

原创 LeetCode413. Arithmetic Slices题解

A sequence of number is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the same.

2017-04-28 21:35:55 339

原创 LeetCode376. Wiggle Subsequence题解

A sequence of numbers is called a wiggle sequence if the differences between successive numbers strictly alternate between positive and negative.

2017-04-18 21:22:46 576

原创 Arduino对57步进电机的控制

最近实验室的智能车从大车路线改到了小车路线，于是笔者也跟着学习一些新的知识。大车的控制可以使用标准的CAN协议，很多方便的指令都能够通过CAN来传输给ECU并得到相应的反馈。然而对于最近接触的电动小白车，控制策略只能使用物理机械去控制。因此使用步进电机拉杆成为目前的解决方案之一。

2017-04-16 00:05:15 27445 9

原创 LeetCode435. Non-overlapping Intervals题解

Given a collection of intervals, find the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping.

2017-04-12 18:44:25 604 1

原创 LeetCode452. Minimum Number of Arrows to Burst Balloons题解

有若干个气球，给出了它们的直径两个端点的坐标（X轴），我们的工作是需要用一支箭来戳破气球。例如两个气球的直径分别是(1,6)和(2,8)，那么我们就可以在x=6的坐标处发射一支箭从而将它们一起戳破。求解的问题是：给出一系列气球直径的坐标之后，最少能用多少支箭就可以戳破它们。

2017-04-10 12:53:35 1171

原创 LeetCode122. Best Time to Buy and Sell Stock II题解

今天讨论一道让我想的过于复杂的题目：一道有关股票买卖的问题。题目描述：Say you have an array for which the i th element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete as many

2017-04-06 16:18:49 488

原创 LeetCode455. Assign Cookies题解

Assume you are an awesome parent and want to give your children some cookies. But, you should give each child at most one cookie. Each child i has a greed factor gi, which is the minimum size

2017-04-03 21:25:59 341

原创 LeetCode406. Queue Reconstruction by Height题解

最近算法课讲到了贪心算法，接下来的几篇题解应该都会与贪心算法相关。1. 题目描述Suppose you have a random list of people standing in a queue. Each person is described by a pair of integers (h, k), where h is the height of the person and k

2017-03-29 11:28:52 268

原创 LeetCode101. Symmetric Tree题解

Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).

2017-03-25 18:17:47 394

原创 LeetCode103. Binary Tree Zigzag Level Order Traversal题解

Given a binary tree, return the zigzag level order traversal of its nodes’ values. (IE, from left to right, then right to left for the next level and alternate between).

2017-03-22 01:20:24 277

原创 LeetCode107. Binary Tree Level Order Traversal II题解

1. 题目描述Given a binary tree, return the bottom-up level order traversal of its nodes’ values. (ie, from left to right, level by level from leaf to root).2. 样例Given binary tree [3,9,20,null,null,15

2017-03-20 19:29:53 279

原创密码学与网络安全笔记整理-数据完整性技术

数据完整性类似于通信中的校验码功能，在密码学领域数据完整性用于验证收到信息的正确性，校验收到的信息是否经过篡改，校验收到的信息是真实的发送者发送而非伪造。发送者通过编码为消息增加一些“冗余”，生成一个校验值，并将该校验值附在消息之后。接收者根据协商好的规则，利用附加的校验值来检测接收到消息的正确性。对称技术，有效的变换f和g是对称算法，意味着f = g，并且Ke = Kv

2017-03-19 23:13:44 8401

原创数媒笔记整理4

1. 题目：Implement Gouraud Shading or Phong Shading based on hw31.1. GoalYou are to write a program to read a set of commands from file and display result on screen.1.2. Commands大部分与《数媒笔记整理3》中的命令相同，这里只

2017-03-18 23:51:59 284

原创数媒笔记整理3

Implement an OpenGL-like 3D Rendering Pipeline.

2017-03-18 22:02:31 294

原创数媒笔记整理2

最近收拾资料，发现之前的数媒笔记只整理了一篇，这几天陆续补上吧。1. 题目：2D transformation, polygon clipping, viewport1.1. GoalYou are to write a program that receive a series of commands, and display result on screen. The commands w

2017-03-18 00:25:57 313

原创 LeetCode513. Find Bottom Left Tree Value题解

1. 题目描述Given a binary tree, find the leftmost value in the last row of the tree.

2017-03-16 20:48:30 453

原创 JPEG编码中的DCT与量化

JPEG是最常用的有损图像压缩算法，而8×8的二维DCT（离散余弦变换）变换和量化又是该算法中的核心步骤。本文作业的例子，是针对一个8×8的数据块进行正反二维DCT变换、量化和反量化

2017-03-16 01:27:51 4060

原创 LeetCode515. Find Largest Value in Each Tree Row题解

1. 题目描述You need to find the largest value in each row of a binary tree.

2017-03-15 16:25:00 306

原创 LeetCode112.Path Sum题解

1. 题目描述Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.

2017-03-13 17:18:47 256

原创 LeetCode110.Balanced Binary Tree题解

1. 题目描述Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never

2017-03-09 19:31:02 292

原创 LeetCode392.Is Subsequence题解

1. 题目描述Given a string s and a string t, check if s is subsequence of t. You may assume that there is only lower case English letters in both s and t. t is potentially a very long (length ~= 500,000)

2017-03-08 20:42:44 403