shadow the dog and
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_{ ......
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 ......
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 ......
Codeforces Round 892 (Div. 2) B. Olya and Game with Arrays
一系列 \(n\) 个数组，第 \(i\) 个数组的大小 \(m_i \geq 2\) 。第 \(i\) 个数组为 \(a_{m_1}, a_{m_2}, \cdots, a_{m_i}\) 。 对于每个数组，你可以移动最多一个元素到另一个数组。 一系列 \(n\) 个数组的 \(beauty\) ......
[CF1168C] And Reachability
And Reachability 题面翻译 题目描述 Toad Pimple 有一个整数数组 \(a_1,\dots,a_n\)。 当 \(x < y\) 且存在 \(x = p_1 < \dots < p_k = y\) 的数列 \(p\) 满足 \(a_{p_i} \& a_{p_{i+1}} ......
[题解]CF514D R2D2 and Droid Army
思路 首先，可以转化题意，找到一个极长的区间 \([l,r]\) 使得（其中 \(mx_i\) 表示 \([l,r]\) 区间中属性 \(i\) 的最大值）： \[\sum_{i = 1}^{m}mx_i \leq k \]显然对于这个东西当 \(l,r\) 发生移动时，是极其好维护的，所以想到双指 ......
CF837G Functions On The Segments
CF837G Functions On The Segments Functions On The Segments - 洛谷 | 计算机科学教育新生态 (luogu.com.cn) 目录CF837G Functions On The Segments题目大意思路code 题目大意 你有 \(n\) ......
Secure Code Warrior C# Basic OWASP Web Top 10 2017 5: Broken Access Control, 6: Security Misconfiguration and 7: XSS vulnerabilities
Learn the ropes or hone your skills in secure programming here. These challenges will give you an understanding of 5: Broken Access Control, 6: Securi ......
Secure Code Warrior C# Basic OWASP Web Top 10 2017 1: Injection Flaws and 2: Broken Authentication vulnerabilities 3: Sensitive Data Exposure and 4: XXE vulnerabilities
Let's continue with some other very common application weaknesses. This set of levels will focus on 3: Sensitive Data Exposure and 4: XXE vulnerabilit ......
Secure Code Warrior C# Basic OWASP Web Top 10 2017 1: Injection Flaws and 2: Broken Authentication vulnerabilities
Let's start with the most critical application weaknesses. These challenges get you the foundations of 1: Injection Flaws and 2: Broken Authentication ......
D. Monocarp and the Set
D. Monocarp and the Set Monocarp has $n$ numbers $1, 2, \dots, n$ and a set (initially empty). He adds his numbers to this set $n$ times in some order ......
Django中出现报错：TypeError: unsupported operand type(s) for /: 'str' and 'str' 时的解决办法
如果遇到上述报错情况 解决办法： 1、点击报错路径，进入源码 2、将' / '替换为' , ' 3、再次运行Django 问题解决。 ......
[908] Implementation of the progress bar in Python
You can implement a progress bar in Python to visually represent the progress of a task using various libraries. One commonly used library for this pu ......
[905] The replace() method in Pandas
In Pandas, the replace() method is used to replace values in a DataFrame or Series. You can use this method to replace one or more specified values wi ......
【转载】How to solve the problem that getting timestamp from Mysql database is 8 hours earlier than the normal time
This article introduces the relevant knowledge of "how to solve the problem of obtaining timestamp from Mysql database 8 hours earlier than the normal ......