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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 ......
bison usage mysql flex and

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 ......
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LEC 1 Introduction Signals Continuous signals EX1.Sound signals \(y = x(t)\) Continuous Time signal() One dimension signal(only have one variable time ......
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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 Staircases LuoguCF Petya 362B

[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 ......
题解 Mysterious String 1881G 1881

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\(\le 1\)) ......
Vitaly Cycle 557D 557 and

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 ......

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 ......
and Setting Tearing Before After

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ARC163D 发现这个竞赛图一定能被分为两个集合 \(A\),\(B\)。满足 \(\forall u\in A,v\in B\),均有 \(u\to v\in E\)。答案就是划分这两个集合的方案数。 证明: 首先,竞赛图缩完点后一定是一条链,对强连通分量进行标号,满足编号小的强连通分量指向编号 ......
题解 性质 163D ARC 163

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, ......
Graphics 笔记 Math Game for

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 ......

linux 中 md5sum -c 命令

001\ [root@pc1 test01]# ls [root@pc1 test01]# seq 3 > a.txt ## 测试文件 [root@pc1 test01]# ls a.txt [root@pc1 test01]# cat a.txt 1 2 3 [root@pc1 test01]# ......
命令 md5sum linux 5sum md5

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 \(beauty\) ......
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[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}} ......
Reachability 1168C 1168 And CF

[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 ......
题解 Droid 514D Army R2D2

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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 ......
Monocarp and Set the

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。 ......
39 unsupported TypeError str operand

CF1168C And Reachability

CF1168C And Reachability And Reachability - 洛谷 | 计算机科学教育新生态 (luogu.com.cn) 目录CF1168C And Reachability题目大意思路code 题目大意 给定一个长度为 \(n\) 的数组 \(a\) 。 你可以选择一个 ......
Reachability 1168C 1168 And CF

CF1548E Gregor and the Two Painters

Day \(\text{叁拾肆}\)。 DS 写不动了,标题也取不动了www。 类似 Day 1 CF1270H Number of Components,每个连通块中选出一个代表的点。令一个连通块内所有点按照 \(v_{i,j}=\{a_i+b_j,i,j\}\) 排序,对最小的 \(v_{i,j ......
Painters Gregor 1548E 1548 and

[论文阅读] Exact Feature Distribution Matching for Arbitrary Style Transfer and Domain Generalization

Exact Feature Distribution Matching for Arbitrary Style Transfer and Domain Generalization 论文源码:https://github.com/YBZh/EFDM 1. Introduction 传统的特征分布匹配 ......

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你在一个向右延申的无限坐标轴上,且你初始在坐标 \(1\) 。有 \(n\) 个陷阱在坐标轴上,第 \(i\) 个陷阱坐标为 \(d_i\) ,且会在你踩上这个陷阱的 \(s_i\) 秒过后发动。这时候你不能进入坐标 \(d_i\) 或者走出坐标 \(d_i\) 。 你需要确定最远的 \(k\) , ......
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原题 翻译 首先 \(O(n^2 \log n)\) 的 dp 是 simple 的,我们设 \(dp_{i,0/1}\) 表示以 \(i\) 为根, \(i\) 到 \(fa_i\) 这条边删/不删的最小权值和。转移是一个非常 trick 的问题,只需要假设所有都选 \(dp_{i,0}\) ,然 ......
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Let’s start with the most critical application weaknesses. These challenges get you the foundations of 1: Broken Access Control and 2: Cryptographic F ......

Leetcode 34. Find First and Last Position of Element in Sorted Array

题解 用了两次二分,分别计算第一个>=target的元素位置和第一个>target的元素位置。闭区间二分,[l,r]是未知的,保证每次答案都在[l,r]中,定义清楚nums[l-1]和nums[r+1]和target的关系。因为是while(l < r),所以到l == r时跳出循环,分析l == ......
Leetcode Position Element Sorted Array

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你需要击败一只巨龙,他有 \(h\) 点血量,你可以使用以下两种攻击方式: 黑洞:使巨龙的血量变为 \(\lfloor \frac{h}{2} \rfloor + 10\) 。可以使用 \(n\) 次。 雷击:使巨龙的血量变为 \(h - 10\) 。可以使用 \(m\) 次/ 当巨龙的血量 \(h ......
Codeforces Dragon Round Quest Kana