Developers Club geek daily blog

Earn on cyberwar

2 years, 4 months ago
It is well known that in time the received insider information about progress and failures of large corporations at the correct stock market game can bring to the owner millions. And at whom how not hackers, have opportunity to get such information or to influence activity of the companies, cracking important business systems? So why not to earn on the knowledge during the forum Positive Hack Days V?

This year participants of PHDays will be able to join life of the state of United States of Soviet Unions (USSU), selling and buying securities at the PHDays Stock Market exchange. Not only participants of CTF and other competitions, but also all visitors of forum will be able to trade in shares provided in competitions? corporations? (directly or through the broker) and to use the insider information for stock market game.

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As I have cracked online casino once

2 years, 5 months ago
Having inspired by the story as it again? has broken the Internet? Egor stop breaking already everything, be engaged in business any, has decided to tell of one history with online casino, quite famous behind the river. Name of this? organizations? I do not call since percent on 50 it is sure that or did not pofiksit at all, or have made krivy, than was before.

The history is very similar to Egor's cracking, except that it not absolutely reys rather not race condition in its pure look at all. As it will be completely I do not know, I more practician, than the theorist. Let's call it? conditional race condition?? though oil buttered, but captures the essence truly.

Somehow in the evening, house have fallen asleep, on box one dregs, ours again lose there was especially especially nothing to do, on opensors has decided to hammer for today, there was a wish to break something. And what to break (when Egor has already broken everything), as not bank any or casino (ego, need sometimes to feel the cool guy, everything has put generally). It was one of the first online casinos which to me then has attracted searching.

It is no secret that save on programmers, testers, etc. all or nearly all. I do by times audits and by the nature of activity of such will sometimes see enough that hair on end. But here casino! With possibility of output (won) evergreen, etc. I.e. the office has to correspond it seems.

Has created to himself account, and have gone?

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In the programming World Cup? Fight of intelligence? the best students from around the world take part

2 years, 5 months ago

The new generation of programmer elite has gathered in Marrakech, Morocco that today, on May 20, to battle in the final of the 39th Student's World Cup in Programming (ICPC) of Association of ADP Equipment as which global sponsor the IBM company acts. The championship takes place under patronage of its royal majesty of the king of Morocco Mohammed VI. This year host the Muhammad's University championship V, University Al Akhaveyn, Mundiapolis's University and ACM Association in Morocco.

The most prestigious competition for programmers to headquarters at Baylor's (Baylor University) University also known as? Fight of intelligence? (Battle of the Brains), for the first time passes on the African continent. The best students programmers from around the world in five hours have to cope with several most difficult tasks from real life. All teams compete for a while in fight of logic, strategy and endurance. Action is sponsored for by IBM. The final was reached by 128 teams of students from universities from around the world which battle for rank of the champion in programming. Winners are already known, results can be viewed at the end of post!

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Odessa Open Class Programming Competition 2015

2 years, 5 months ago
Our FlyElephant team actively supports different actions and today we want to invite all to annual competition of programmers? Open Class Programming Competition which will pass on May 31 in the Odessa national university of I. I. Mechnikov.

This year competition is dated for celebration of the 150 anniversary from the date of foundation of university.

The main feature of competition are the most democratic conditions of participation and carrying out. School students, students, teachers, professional programmers and talented fans can participate in competition. It is possible to participate in competition even anonymously.

Competition will take place at the same time in two modes? internal and online. For participation in competition it is necessary to be registered on the site http://codelands .com.

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Analysis of problems of the 2nd qualification round of Russian Code Cup 2015

2 years, 5 months ago

On Saturday April 25 has passed the second qualification round of Russian Code Cup 2015. 3516 programmers solved problems within two hours, from them at least one correct solution was sent by 458 participants.

The first in 4 minutes and 9 seconds Masharabov Alexander (map) has solved A problem (Tourniquets in the subway). The problem of B (Game) for 8:48 was solved by Dublennykh Denis (Stigius), the problem of C (Sticks and hinges) for 18:08 was solved by Nigmatullin Niyaz (niyaz.nigmatullin). The problem of D (Fibonacci's Numbers) in 1 hour 5 minutes and 21 seconds was solved by Lunev Anton (Anton_Lunyov). And the last problem of E (Teleports) in 1 hour 44 minutes and 55 seconds was solved by Kunyavsky Pavel (PavelKunyavskiy) who has taken 1 place in rating following the results of round. The last successful attempt is made by Albert Saakian in 4 seconds until the end of competition. All five tasks were handed over only by Pavel Kuyavsky.

In total participants have sent for check of 4287 solutions, on With ++ them was 3145, on Java? 613. Let's note that from 2166 solutions which are handed over on GNU C ++, 1218 solutions use With ++ the 11th standard, and the others still do not apply new opportunities of language. The correct solutions this time only 913, from them on With ++? 726, on Java? 141.

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Whether experience and achievements in sports programming in real life and work help, or disturb?

2 years, 6 months ago
Sports programming? very ambiguous subject. One consider, what achievement in it? good indicator of talent and abilities for industrial development, others? that such experience does rather harm.

For example, has told that in Google there is negative correlation between victories of the person at the Olympic Games for programmers and its progress in work. In his opinion, sports programming accustoms to concentrate on momentary tasks whereas at work it is necessary to think of the future of the project.

Due to the approach of Yandex. Algorithm, our own sports programming championship, we have decided to ask developers from Yandex who as participated and won on different contests, and is not present, whether experience in sports programming in programming industrial helps?

All stages of Yandex. Algorithm this year will take place in online so those who is not ready to go somewhere will be able to participate in it also. The algorithm consists of several selection rounds, in each of which it is necessary to solve five problems in 100 minutes. In the final which will take place on August 6, there will be 25 the best by results of selection. The training round to which it is worth being registered, will pass on May 3.

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Watch online broadcast of Imagine Day on April 18

2 years, 6 months ago

Dear friends!
We invite you to the main student's event of this spring? IMAGINE DAY!
Imagine Day? it is the Russian final of Imagine Cup and Student Day. Action will take place on April 18, 2015, from 9:00 till 18:00, in the Technopolis Moscow Congress center. For those who lives far and will not be able to arrive to Moscow? we will organize online broadcast of reports and interview to teams on the site Beginning of broadcasting at 10:00 (MOSCOW TIME). You are waited by live broadcasts from site, interview to participants, and also conversations with jury!

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New superblitz on Java-hardcore

2 years, 6 months ago
So, yesterday we have played dzhavovsky option? Intellectual casino against experts?, and thus, at all respect for habrovchana, TV viewers have won! Sergey SerCe Tselovalnikov who has solved three problems became the winner of this stage. As promised? we award to it small prize: VIP-ticket for JPoint!

But pleasures aside. Yesterday we with TV viewers were accused that the majority of yesterday's tasks have been connected with Java very indirectly. We accept this charge and therefore today we have option on pure Java! any spring, eksemely and patterns. It will be the real testing for true fans of hardcore!

Under cat? answers to yesterday's round and superblitz! Against experts the TV viewer from St. Petersburg Andrey of apangin Pangin plays today.

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Simple tasks on Java. Poorly to solve everything?

2 years, 6 months ago

Hi! We have collected party of one of the coolest Russian-speaking Java-experts here and have asked them to give brain on task that you have broken teeth, and fought about wall, trying to understand how it works. Actually, we have argued on Hennessey's bottle that in 12 hours after the publication nobody will send all correct answers. I am sure that someone will be able. Therefore if you will make it the first? from me bottle.

The first task simple, it from the TV viewer Nikolay Garbuzov, the rolling pins specialist loving recursion, pattern-matching and magic of compilation:
Whether the following aspect will be compiled by the AJC compiler?
If yes? that will it bring that to the console at compilation?

public aspect QuizAspect {
    public static int count(int i) {
        return i++;

    before (int n) : execution(public int QuizAspect.count(int)) 
            &&args(n) &&if(QuizAspect.count(1)>1) {
        System.out.println("QuizAspect " + n);

So far it is simple, the truth?

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Algorithms of fast calculation of factorial

2 years, 6 months ago
The concept of factorial is known to all. It is the function calculating work of consecutive natural numbers from 1 to N inclusive: N! = 1 * 2 * 3 *? * N. Factorial? fast-growing function, already for small values N value N! has many significant figures.

Let's try to implement this function in programming language. Obviously to be necessary for us the language supporting long arithmetics. I will use C#, but with the same success Java can be taken or Python.

Naive algorithm

So, the elementary implementation (we will call it naive) turns out directly from definition of factorial:

static BigInteger FactNaive(int n)
    BigInteger r = 1;
    for (int i = 2; i <= n; ++i)
        r *= i;
    return r;            

This implementation works about 1,6 seconds for N=50 000 at my machine.

Further we will consider algorithms which work much quicker than naive implementation.

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