monocarp and set the
flex and bison usage in mysql
query parsing in mysql mysql source code version: 8.0.34 (from MYSQL_VERSION file) This an article from questions to understandings. which file does m ......
python websocket server and client 用户认证
WebSocketServer.py pip install websockets #!/usr/bin/env python3 # -*- coding: utf-8 -*- # @mail : lshan523@163.com # @Time : 2023/10/18 9:58 # @Autho ......
Signals and systems（1）
LEC 1 Introduction Signals Continuous signals EX1.Sound signals \(y = x(t)\) Continuous Time signal() One dimension signal(only have one variable time ......
LuoguCF362B Petya and Staircases 题解
分析 简单排序题。 首先 Petya 可以通过跨过一个台阶和两个台阶保证不经过脏台阶，但是不可以通过跨过三个台阶来保证不经过脏台阶，所以只要看有没有连续的三个脏台阶即可。 同时，如果第一个台阶和最后一个台阶至少一个是脏台阶那么就不可以达成。 Accepted Code /*Code By Manip ......
[题解]CF1881G Anya and the Mysterious String
思路 发现如果一个字符串中有长度大于等于 \(2\) 回文子串，必定有长度为 \(2\) 的回文子串或长度为 \(3\) 的回文子串，并且形如：aa 和 aba。 所以考虑用线段树这两种情况。维护一段区间的最左、次左、最右、次右的元素，同时用两个标记变量 \(f_1,f_2\) 分别表示这个区间中是 ......
PAT_A 1038 Recover the Smallest Number
Given a collection of number segments, you are supposed to recover the smallest number from them. For example, given { 32, 321, 3214, 0229, 87 }, we c ......
How to get macOS CPU details information in the command line All In One
How to get macOS CPU details information in the command line All In One
如何通过命令行获取 macOS CPU 的详细信息
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[QOJ6555] The 2nd Universal Cup. Stage 5. J : Sets May Be Good
先给 EI 磕三个 首先考虑用 \(n\) 个变量 \(x_1,x_2,\cdots,x_n\in\{0,1\}\) 表示第 \(i\) 个点选不选，那么导出子图的边数的奇偶性就是 \[f(x_1,x_2,\cdots,x_n)=\left(\sum_{(i,j)\in E}x_ix_j\right ......
asp.net core signalr 客户端调用服务端方法报：Error:Failed to invoke 'adduserToConnection' due to an error on the server
TS端调用方法为： connection.start() .then(() => { connection.invoke("adduserToConnection",account,connection.connectionId); }) .catch((err) => { console.erro ......
CF1257E The Contest
用桶存，做一遍前缀和，令 \(b_{x,y}\) 表示序列 \(x\) 包含 \(1\sim y\) 的数字个数。考虑枚举第一个序列保留的前缀 \(1\sim i\)，对于第三个序列，如果其保留了后缀 \(j\sim n(i<j)\)，考虑哪些数需要被移掉，那么答案就是： \[b_{1,n}-b_{ ......
solution set#1
The Very Beautiful Blanket Problem - A - Codeforces 题意 构造一个\(n\times m\)的矩阵，使其中每个\(4\times 4\)子矩阵中，右上角的\(2\times 2\)异或和与左下角的\(2\times 2\)异或和相等，左上角和右下角 ......
kotlin 属性的get和set方法
一、属性的继承 1、属性和函数类似也是可以继承 interface Parent { val addr: String // 这里是接口所以默认是open，如果是普通类中要被继承则需要显示写open } class Child: Parent { override val addr: String ......
The 2nd Universal Cup. Stage 5: Northern J Sets May Be Good
题解 我们考虑计算 \(\sum_{S\subseteq\{1,2,3,\cdots,n\}} (-1)^{cnt(S)}\)，这里 \(cnt(S)\) 表示 \(S\) 集合的导出子图的边数。 我们记 \(x_i=[i\in S]\)。 我们考虑删掉 \(n\) 号点。 注意到如果 \(x_i\ ......
【题解 CF840C & P4448】 On the Bench & 球球的排列
On the Bench 题面翻译 给定一个序列 \(a(a_i\le 10^9)\)，长度为 \(n(n\le 300)\)。 试求有多少 \(1\) 到 \(n\) 的排列 \(p_i\)，满足对于任意的 \(2\le i\le n\) 有 \(a_{p_{i-1}}\times a_{p_i} ......
Go - Changing the Timing for Running Performance Tests
Problem: You want to run performance tests for a specific duration or a specific number of iterations. Solution: You can increase the minimum duration ......
论文阅读：Knowledge Distillation via the Target-aware Transformer
摘要 Knowledge distillation becomes a de facto standard to improve the performance of small neural networks. 知识蒸馏成为提高小型神经网络性能的事实上的标准。 Most of the previo ......
达梦数据库 -2723: 仅当指定列列表，且SET IDENTITY_INSERT为ON时，才能对自增列赋值
达梦数据库 -2723: 仅当指定列列表，且SET IDENTITY_INSERT为ON时，才能对自增列赋值 一、问题背景 达梦数据库 -2723: 仅当指定列列表，且SET IDENTITY_INSERT为ON时，才能对自增列赋值 二、问题原因 三、解决方案 ......
Nginx配置错误：connect() failed (10061: No connection could be made because the target machine actively refused it) while connecting to upstream
问题描述 今天本打算学一下Nginx反向代理发送请求到OpenResty(其实也就是个Nginx，可以把它理解成Anaconda中的python版本)，再通过OpenResty使用Lua脚本向Redis或数据库查找缓存来着，在配环境的时候报了个502错误。 我把我的环境描述下，这样如果有遇到这个问题 ......
ERROR: The Python ssl extension was not compiled. Missing the OpenSSL lib?
CentOS7 pyenv安装Python 3.10.13 报错 yum install -y openssl-devel openssl11-devel openssl11-lib CPPFLAGS="-I/usr/include/openssl11" LDFLAGS="-L/usr/lib64/ ......
[914] In Python's datetime library, you can format dates using the strftime() method
In Python's datetime library, you can format dates using the strftime() method. This method allows you to create a formatted string representation of ......
论文阅读 Generalized Focal Loss: Learning Qualified and Distributed Bounding Boxes for Dense Object Detection
原始题目：Generalized Focal Loss: Learning Qualified and Distributed Bounding Boxes for Dense Object Detection 中文翻译：Generalized Focal Loss：学习用于密集目标检测的 Qual ......
CF557D D. Vitaly and Cycle
小清新分类讨论题 首先不难发现这题加边的上界就是\(3\)，并且只有当图中一条边没有时才会取得，方案数就是\(C_n^3\) 而一条边不加的情况也很容易，可以先跑个染色看下有没有奇环，如果有的话就直接输出即可 而加两条边的情况也比较简单，当图中都是孤立边和孤立点时（即所有点度数均\(\le 1\)） ......
[911] Read Data from Google Sheets into Pandas without the Google Sheets API (.gsheet)
ref: Read Data from Google Sheets into Pandas without the Google Sheets API import pandas as pd sheet_id = "1XqOtPkiE_Q0dfGSoyxrH730RkwrTczcRbDeJJpqRB ......
Expression #3 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'jira.ji.ID' which is not functionally dependent on columns in GROUP BY clause;only_full_group_by
这个报错的完整信息 Expression #3 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'jira.ji.ID' which is not functionally dependent on ......
definition of the convex optimization
A convex optimization problem is one in which the objective and constraint functions are convex, which means they satisfy the inequality \(f_i(\alpha ......
Go - Setting Up and Tearing Down Before and After Tests
Problem: You want to set up data and an environment for testing and tear it down after the test is run. Solution: You can create helper functions or u ......
The solution of P9194
10黑寄。 problem & blog 考虑到处理加边并不简单，所以我们可以考虑一个黑点 \(p\)，连边\((u,p)(p,v)\)。 考虑在现在这棵树上连个点在原图中有变相连相当于有一个公共的 \(p\) 是它们的邻居。 于是删边操作等价于将一个点的儿子黑点并到父亲黑点上。 为了统计答案我们设 ......
3D Math for Graphics and Game笔记
这个机器人的原点在世界坐标系下的(4.5,1.5),而她右肩膀上的那个灯的模型坐标系为(-1,5),怎样计算这个灯的世界坐标呢？ 开始： 获取原点，这个原点为(4.5,1.5) 向右移动一个位置，机器人的"左边"是[0.87,0.50],这样得到的位置为(4,5,1.5) + (-1)X[0.87, ......
ORA-01078: failure in processing system parameters ORA-00093: pga_aggregate_limit must be between 2048M and 100000G
在启动数据库实例时报错： ORA-01078: failure in processing system parametersORA-00093: pga_aggregate_limit must be between 2048M and 100000G 原因： 该报错是由于设置的pga_aggre ......
Secure Code Warrior C# Basic OWASP Web Top 10 2017 8: Insecure deserialization, 9: Using Components with Known Vulnerabilities, 10: Insufficient Logging and Monitoring
Last but not least. These set challenges consist of 8: Insecure deserialization, 9: Using Components with Known Vulnerabilities, 10: Insufficient Logg ......