Sword finger Offer programming problem (Java implementation) -- repeated numbers in array

Title Description All numbers in an array of length n are in the range of 0 to n-1. Some numbers in the array are repeated, but I don't know how many are. I don't know how many times each number is repeated. Please find any duplicate number in the array. For example, if the input length is 7 array {2,3,1,0,2,5,3}, the corresponding output is t ...

Posted on Thu, 17 Oct 2019 11:24:42 -0700 by JeditL

Solution to the problem of NOIP2017 improvement group

Unconsciously, NOIP is slowly coming. Recently, I will start to brush some questions similar to the difficulty of NOIP. I have done the problem of NOIP2017 in my spare time. I feel that it is obvious to distinguish the difficulty of NOIP2018d2... d1t1 Xiaokai's doubts Not much, conclusion \ (a * b - a - b \). Code slightly. Time complexity of d ...

Posted on Thu, 17 Oct 2019 11:03:11 -0700 by mkarabulut

Learning of mybatis

(this case is listed under maven project:) 1. Establishment of experimental environment: (a student table, a teacher table) CREATE TABLE `teacher` ( `id` INT(10) NOT NULL, `name` VARCHAR(30) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=INNODB DEFAULT CHARSET=utf8 INSERT INTO teacher(`id`, `name`) VALUES (1, 'Teacher Qin'); CR ...

Posted on Wed, 16 Oct 2019 11:11:58 -0700 by brighton

Mybatis -- input mapping in mapper.xml

6. Input mapping The type of input parameter is specified by parameterType, which can be simple type, hashmap, POJO packing type. 6.1 packaging object of POJO 6.1.1 demand To complete the comprehensive query of user information, the query conditions that need to be passed in are very complex (may include user information, other information, ...

Posted on Wed, 16 Oct 2019 10:27:58 -0700 by gentusmaximus

[comet OJ - contest ා 7 d] [52d 2417] machine learning problem ා slope optimization dp

Machine learning questions Main idea: Data range: Explanation: Is it monotony of decision-making? It's better to optimize the slope directly. The first thing to discover is that the values of $A $and $B $must be some two $x $values. Then we divide the positive and negative of $y $into two sequences, $val1 i $means that $A $takes the ...

Posted on Wed, 16 Oct 2019 08:35:40 -0700 by kalinkap

thinkphp5 combined with Swoole to develop WebSocket online chat communication system

To use Swoole in ThinkPHP, you need to install the think Swoole composer package, provided that the system has installed the Swoole PECL extension. To install think swoole, execute the composer command in the project root directory of tp5: composer require topthink/think-swoole If you don't say much, go straight to the code: To create a WebSock ...

Posted on Wed, 16 Oct 2019 08:35:14 -0700 by coldfiretech

Experiment: building LAMP

Environmental Planning: Prepare three virtual machines 192.168.50.136: web 192.168.50.140: mysql 192.168.50.142: memcached First, three virtual machines are operated as follows: ① turn off the firewall, ② synchronize the time, ③ uninstall MariaDB LIBS and postfix; web server settings In 192.168.50.136 ...

Posted on Tue, 15 Oct 2019 11:38:09 -0700 by akufen

php's method for wechat payment callback processing (Collection)

Wechat needs to receive payment results through asynchronous callback, whether it is wechat's built-in JSAPI payment, H5 external browser payment or scanning payment. This article introduces how to get wechat payment notice. Just write the following in the previously set callback address method:   //Process wechat payment callback ...

Posted on Tue, 15 Oct 2019 10:11:11 -0700 by glima

How to de duplicate array slices by Go

The Go standard library itself does not provide a function to remove duplicate elements from slice, which needs to be implemented by itself. The following provides an implementation idea. If there is a better implementation method, please leave a message for discussion. package main import ( "fmt" ) func main() { s := []string{"hello" ...

Posted on Tue, 15 Oct 2019 09:32:26 -0700 by angelcool

Second Kill Solution in High Concurrent Business Scenario (Preliminary Study)

Prodigal Programming goes in all directions Author: The prodigal son programms to go all directions, diligently records, understands to share, deliberately practices, daily improvement! Public Number: Talk late at night Article brief introduction The content of this article is a solution to the problem of oversold in concurrent business scenar ...

Posted on Mon, 14 Oct 2019 20:57:16 -0700 by cityboy101