Some problems of school mathematics

Based on articles "About one task that is no longer offered at the interview."
 
 
First, let's look at a task that you can still offer at an interview.
 
 
38. Calculate the amount ("Tasks for children from 5 to 15 years")
 
 
Some problems of school mathematics
 
(with an error of not more than 1% of the answer)
 
 
The algorithm for calculating the partial sums of this series in the language Scheme (Lisp) in the drRacket environment (drRacket allows to perform calculations in ordinary fractions):
 
#lang racket
(define series_sum
(lambda (n)
(if (= n 0) 0
(+ (/1 (* n (+ n 1))) (series_sum (- n 1)))
)) )
(series_sum 10)
(series_sum ...
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Why in the near future complex proposals will form the basis of retail

To improve the quality of customer service and provide consumers with a wide choice, retailers break large trade offers into narrowly focused services. The author of the article discusses how effective such strategies are, and why well-thought-out integrated solutions can turn out to be more profitable.
 
 
Why in the near future complex proposals will form the basis of retail
 

Banking services are broken down into separate segments


 
The implementation of the concept of open banking began with the release of the legislative act PSD2 . According to the concept, licensed third parties can ...[/h]
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Cellular operators still cancel charges for national roaming

Cellular operators still cancel charges for national roaming  
 
Federal operators VimpelCom, MegaFon and MTS are planning to cancel the fee for incoming calls in intranet roaming in the near future. As for VimpelCom (Beeline brand), this will happen no later than August 20. Thus, if the subscriber uses communication services in the operator's network, outside the "home" region, then there will not be a need to pay.
 
 
Now for incoming calls the subscriber pays about 5 rubles in national roaming. for a minute of conversation - in the event that the call came from another region, writes ...
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How to make a user search using GitHub using React + RxJS 6 + Recompose

How to make a user search using GitHub using React + RxJS 6 + Recompose
 
This article is intended for people with experience working with React and RxJS. I just share the templates that I found useful for creating this UI.
my repository on GitHub.
 
git clone https://github.com/yazeedb/recompose-github-ui
cd recompose-github-ui
yarn install

 

In the branch. master there is a ready project. Switch to start if you want to go one step further.


 
    git checkout start    

 

And run the project.


 
    npm start    

 

The application should start at localhost: 3000 and ...

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Vulnerability in Telegram allows to compromise secret chats

Vulnerability in Telegram allows to compromise secret chats

Dedicated to the anniversary Telegram


 
In secret telegrams Telegram uses "end-to-end encryption", and what? End to end encryption Telegram weakly protects the correspondence of users. A simple example: an attacker took out Alice's private gpg key, of course, to decrypt a message encrypted for Alice, a password from this key is needed, which can not be quarantined, adhering to the modern doctrine of password protection. In Telegram end to end encryption on Android - it becomes possible with a probability of 100%. Bypassing two-factor authentication, restoring the pin code and hijacking secret ...[/h]
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ASAP assesses Boeing's malfunction and SpaceX's successes before announcing the crew composition of

Translation of the article from July 3? the original is available by
 
 
As NASA prepares to name updated launch dates for unmanned and manned demonstration flights under the Commercial Crew program, and to appoint crews for SpaceX and Boeing, the Aerospace Safety Advisory Panel (ASAP) advisory group on Thursday held a quarterly meeting. At this meeting, ASAP identified a problem on the part of Boeing, which could potentially lead to the redesign of the critical node Starliner. ASAP also highlighted several positive points about SpaceX.
 
 
 
[h4] Boeing suffers a critical malfunction on Starliner: ...[/h]
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Programming with the mouse: how we escape from routine with CRM

Programming with the mouse: how we escape from routine with CRMWhat is the programming with the mouse? This is the principle of creating a user interface, which allows you to get away from writing code. Many people criticize this approach: they say that mouse programming is unworthy of a real developer, everything should be in code. But before even to draw a circle, it was necessary to know the basic syntax of the same Basic. Now any user can draw any shape in any simplest graphic editor, and this is not even called programming, since the operation is too simple. This is the development of the user interface, which makes it easier to interact with the computer...
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Explanation of lambda expressions

Explanation of lambda expressions
 
I have questions about lambda expressions and RxJava. These questions mainly concern not a complete understanding of lambda expressions or RxJava. I will try to explain lambda expressions as simply as possible. RxJava I will describe separately.
 
Lambda expressions and RxJava
 
What are lambda expressions? Lambda expressions are "just" a new way of doing the same thing that we could always do, but in a purer and less verbose new way of using anonymous inner classes.
 
An anonymous inner class in Java is a class with no name, it should be used if you need to override class or interface methods. An anonymous ...
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Do not be afraid of microservice: Alexey Baitov about the use of microservice architecture in practice

Do not be afraid of microservice: Alexey Baitov about the use of microservice architecture in practiceFor some, microservices are an opportunity to remake and refactor an application under a conditionally modern style. Another this architectural solution is not suitable because of the peculiarities of interaction between different parts of the application. In any case, when choosing architecture, it is useful to study someone else's experience of moving from a monolith to a set of services.
 
 
We asked to share our development and delivery case for Alexey Bayitov, a leading engineer of the 2GIS. Let's talk about the architectural solutions, deploy and scalability. We will ask about trend and simple ...
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As a "no-brand" startup has received $ 240 million to defeat the Amazon

Masayoshi Son is known for his profitable investments. In 199? his SoftBank fund invested $ 1 million in Yahoo, which in three years yielded $ 3 billion. In 200? the company gave $ 20 million to Chinese Alibaba - and by September 201? when it entered the IPO, they turned into $ 60 billion. Who will the next brand that will blow up the market? Masayoshi Seon believes that this will not be a brand at all.
 
As a "no-brand" startup has received $ 240 million to defeat the Amazon  
 
Now his SoftBank with assets for $ 220 billion has a new pet - Brandless, a store without brands. At the meeting with Masayoshi Song in March, the founders of this start-up from San Francisco left ...
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