ARTS is an activity launched by Chen Hao in the geek time column, aiming to stick to learning through sharing.
Each person writes an ARTS every week: Algorithm is an Algorithm problem, Review is to read an English article, technology / tips is to Share a small technology, and Share is to Share a point of view.
This week's ARTS yo ...
Posted on Mon, 15 Jun 2020 00:16:24 -0400 by char skd1
Ten sorting algorithms are implemented in Python. There is only a simple explanation and no detailed introduction of the algorithm.
Stable sorting: if a is in front of B, and a==b, a is still in front of B after sorting, it is a stable sorting.
Unstable sorting: if a is originally in front of b, and a==b, and a may not b ...
Posted on Sun, 14 Jun 2020 01:03:51 -0400 by tazz
==> Learning summary (continuous update)
==> Build back-end infrastructure series from scratch (I) -- background introduction
Summary: Part I A simple lockless thread pool is realized, novelette This paper focuses on the analysis of java thread pool source code.
1, Basic conceptsIn fact, to under ...
Posted on Sat, 13 Jun 2020 06:38:28 -0400 by drummerboy
Point Cloud Filtering
When acquiring point cloud data, due to the impact of equipment accuracy, operator experience, environmental factors and other factors, some noise points (that is, points we can't use) are inevitable in point cloud data. We need to remove these points when proces ...
Posted on Sat, 13 Jun 2020 04:14:43 -0400 by jeremuck
1 project construction
1.1 new project and operation
1.2 configure basic appearance according to project effect
2. Frame up
2.1 configure tabbar
3 get data from the background
3.1 package request component
3.2 build background application
4 home page
4.1 configure basic data of home page ...
Posted on Sat, 13 Jun 2020 03:34:05 -0400 by hash1
rip and ospf routing protocol
rip routing protocol
The difference between rip and rip2
Frequently asked questions
ospf routing protocol
Implementation proce ...
Posted on Sat, 13 Jun 2020 03:24:24 -0400 by j007ha
Based on the principal component analysis of the scores of 50 students in the table below, how many comprehensive variables can be selected to represent the scores of these students in 6 courses?
The data are as follows:
1. Data import and data standardization
> data=read.csv('D:/R languaga_ma ...
Posted on Sat, 13 Jun 2020 02:20:51 -0400 by php_east
Slow Query Log
Understanding slow queries
mysql's slow query is a type of log record provided by mysql that records statements whose execution time exceeds the set threshold.This time-out is configurable, and the default time-out is 10s, which is then written to the log.Then combined with explain to ...
Posted on Fri, 12 Jun 2020 22:13:07 -0400 by john9292
Chemistry is amazing. Here are the alkyl groups.
Suppose, as shown above, this alkyl group has six atoms and five chemical bonds, six atoms labeled 1-6, and then a pair of numbers a and b denotes that there is a chemical bond between atom A and atom b.This allows a description of an alkyl ...
Posted on Fri, 12 Jun 2020 21:22:51 -0400 by pgudge
1. What is a subquery
-- Requirements: Query who is in the development department
select * from emp;
-- Query by two statements
select id from dept where name='Development Department' ;
select * from emp where dept_id = 1;
-- Use subqueries
select * from emp where dept_id = (select id from dept where name='Marketing Department');
Posted on Fri, 12 Jun 2020 13:09:12 -0400 by JeffK