Hello CodeForces community!

With great enthusiasm and excitement, I would like to invite you to register for CodeChef’s 5th edition of SnackDown which is open to anyone who has a knack for programming. In a truly global spirit of competition, CodeChef organizes SnackDown with an aim to bring the top coders from the world under one roof for its final onsite round in India. Along with the total cash prizes of $20.5K , there are special slots and prizes for Top School Teams, Top Girls teams and Best Indian Teams. And of course the chance to experience a fully sponsored trip to India.

To know how it feels to be an onsite finalist at SnackDown, Have a glance at last year’s SnackDown video here- https://www.youtube.com/watch?v=_rsFuDcUC54

The registrations for the online rounds of SnackDown have begun, You can register a team upto 2 or go solo!

To register, go to — https://www.codechef.com/snackdown

If you are a programming enthusiast who likes to spread the love for coding by spreading awareness about competitive programming, join our SnackDown Representative Program — https://www.codechef.com/snackdown/2019/srp#about. The objective of the program is to spread the awareness about SnackDown and competitive programming among students and professionals alike across various institutes/organisations.

После долгого перерыва (болезнь, конференция и много других вещей) состоится новый Div.3 раунд!

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Привет! В 12.10.2018 17:35 (Московское время) начнётся Codeforces Round 515 (Div. 3) — очередной Codeforces раунд для третьего дивизиона. В этом раунде будет 6 или 7 задач, которые подобраны по сложности так, чтобы составить интересное соревнование для участников с рейтингами до 1600. Наверное, участникам из первого дивизиона они будут совсем не интересны, а для 1600-1899 покажутся простыми. Однако все желающие, чей рейтинг 1600 и выше могут зарегистрироваться на раунд вне конкурса.

Раунд пройдет по правилам образовательных раундов. Таким образом, во время раунда задачи будут тестироваться на предварительных тестах, а после раунда будет 12-ти часовая фаза открытых взломов. Я постарался сделать приличные тесты — так же как и вы буду расстроен, если у многих попадают решения после окончания контеста.

C++ has always had the convenient data structures std::set and std::map, which are tree data structures whose operations take time. With C++11, we finally received a hash set and hash map in std::unordered_set and std::unordered_map. Unfortunately, I've seen a lot of people on Codeforces get hacked or fail system tests when using these. In this post I'll explain how it's possible to break these data structures and what you can do in order to continue using your favorite hash maps without worrying about being hacked

Привет, Codeforces!

В 11.10.2018 17:50 (Московское время) состоится Educational Codeforces Round 52 (рейтинговый для Див. 2).

My friends from Harbour.Space and Remy Robotics asked to publish the news. I am excited and glad to do it, because for our community this is a true exclusive offer. In short, they offer to study robotics in Barcelona, paying for your studies and even with a scholarship! It's so cool!

Here is a direct speech from Harbour.Space.

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Hi Codeforces!

We are excited to announce our new Master’s in Robotics programme scholarship, which will be paired alongside an internship with our partner Remy Robotics! The programme will begin on January 7th, 2019, at our university in Barcelona, Spain.

Harbour.Space’s Robotics programme is the bridge between a personal interest in the world of Robotics, Artificial Intelligence, and a top-level professional future in one of the most exciting and fastest growing fields of technology. Students who enter the programme will either graduate as Control Engineers (theoretical specialists who ensure that robots interact with the environment in safe and effective manner), or CV Engineers (industrial manufacturers of robots, based more on practical experience).

Students will learn the Design and Control for Dexterous Manipulation; Kinematics, Dynamics and Control; Advanced Manipulation Algorithms robots use to physically interact with their world; Dynamic Optimisation for behavioral control; Integrated Intelligence in Robotics: Vision, Language, and Planning which builds upon the cognitive development; Mechanics of Manipulation focusing on using intelligent development of kinematic constraint, gravity, and friction; Manipulation, Estimation, and Control allowing for robots to locomote and navigate the world; Reinforcement learning in Robotics.

SCHOLARSHIP VALUE: €34,900

The scholarship includes:

• Complete coverage of the University tuition fee (€22,900)

• Living allowance (€1,000 per month during 1 year)

• Internship at Remy Robotics (20h per week during 1 year)

REQUIRED EDUCATION:

Bachelor's or Master's Degree in Robotics or Computer, Electrical, Mechanical Engineering or related disciplines.

QUALIFICATIONS AND SKILLS:

• Hands-on robotic programming
• Ideally experience within the automotive manufacturing sector
• Knowledge understanding of robot control interface with ancillary equipment
• Use of robot simulation packages
• Deep experience with all things robotic, from infrastructure-free autonomy to ROS, computer vision, and machine learning
• Experience working with robot parts and components, developing robotics devices
• Ability to concurrently manage multiple diverse and often complex issues and / or projects at the nexus of software, sensors, and hardware

To be selected for this programme, you will need to go through the following steps:

1. Fill out the given form by the link: https://codeforces.net/userForm/89f420923cb55373
2. Attend a series of online tests and interviews with our admissions office and partners
3. Pack your bags for Barcelona!

Hungry for yet another contest? On Sunday, October 7, 2018 at 17:05 UTC the Lyft Level 5 Challenge will start with the Round 1! This is a combined round having 7 problems and lasting 2 hours, and it will be rated.

The top 100 participants of this round will win a Lyft Level 5 Challenge t-shirt. The top 30 contestants located in the San Francisco Bay area will be invited to the Final Round.

In the Final Round the top three onsite contestants will fight for the cash prizes:

• First place: $2000
• Second place: $1000
• Third place: $500

Many thanks to:

• arsijo for the round coordination,
• fhlasek, KAN, Nazikk, Sonechko, stanislav.bezkorovainyi, MaxZubec for testing the round
• MikeMirzayanov for Codeforces and Polygon platforms
• Lyft for sponsoring the round
• Alice and Bob for playing a crucial role in some of the statements

I'll be on the community Discord server shortly after the contest to discuss the problems.

UPDATE 1: The scoring distribution will be 500-1000-1500-2250-2750-3250-4000.

UPDATE 2: The contest is over and there is an editorial.

UPDATE 3: Congratulations to the winners:

1. tourist
2. V--o_o--V
3. DearMargaret
4. Errichto
5. 300iq

We are thrilled to announce the Lyft Level 5 Challenge hosted by Codeforces and sponsored by Lyft. This international competition consists of two, timed rounds, where competitors will solve multiple algorithmic puzzles much like the ones we’re solving at Level 5, Lyft’s self-driving division.

Round 1: Elimination

On Sunday, October 7, 2018 at 10:00 PDT, the competition kicks off with a standard two-hour round of seven problems. The top 100 participants will win a Lyft Level 5 Challenge t-shirt. The top 30 contestants located in the San Francisco Bay area will be invited to Round 2.

Round 2: Final at Level 5

On Sunday, November 4, 2018 at 10:00 PST, round 2 kicks off with a standard two-hour round of five problems. Up to 30 contestants will compete for prizes at the Level 5 Engineering Center in Palo Alto, California, and Codeforces will host a parallel round for offsite participants. After the challenge, stick around for a Level 5 team social.

Round 2 Prizes

• First place: $2000
• Second place: $1000
• Third place: $500

Terms and conditions apply.

About Level 5

Level 5 is Lyft’s self-driving division based in Palo Alto, California, and Munich, Germany, where we’re building a full self-driving system. Engineers at Level 5 are equipping vehicles with the latest advancements in sensors and applying deep learning to predict and perceive the world around us. We’re leveraging route by route data from the 10 million Lyft rides completed weekly to both rapidly advance our technology and train our vehicles.

Every member of our fast-moving, collaborative team has the opportunity to have an outsized influence on our self-driving development. And we’re passionate problem solvers, too. Meet Vladimir Iglovikov [kaggle], Viktor Barinov [cf, tc], and Alex Lapin [kaggle, cf, tc].

Help define the future of self-driving technology with us at Level 5. See our open roles at lyft.com/level5, and follow us on Twitter @LyftLevel5.

What is Lyft?

Lyft is the fastest growing ridesharing company in the United States with coverage for over 95% of Americans in all 50 states. We’re working toward our mission of improving people’s lives with the world’s best transportation.

Всем привет!

Завтра (5 октября, 17:35 (UTC+3)) состоится Codeforces Round #514 (Div. 2). Раунд будет рейтинговым для второго дивизиона (рейтинг ниже 2100). Участники из первого дивизиона могут написать контест вне конкурса.

Выражаю благодарность KAN за его помощь с задачами и координацию раунда, Aleks5d и Um_nik за тестирование раунда и, конечно, MikeMirzayanov за замечательные платформы Codeforces и Polygon.

Вам будет предложено 5 задач и 2 часа на их решение.

UPD: разбалловка 500-1000-1500-2000-2500

UPD2: Поздравляем победителей!
Div. 2:
1. qingczha
2. PaidySung
3. Hyperbolic
4. memopaper
5. reku

Оба дивизиона:
1. Radewoosh
2. qingczha
3. natsugiri
4. nuip
5. PaidySung

UPD3: разбор

Удачи!

On Oct/04/2018 10:05 (Moscow time), the Codeforces Round 513 by Barcelona Bootcamp (rated, Div. 1 + Div. 2) will start. This is a special round for the Hello Barcelona Programming Bootcamp, in collaboration with Moscow Workshops ICPC. It is rated for all participants, everybody can register on it regardless of a rating.

Hello Barcelona Programming Bootcamp is sponsored by VTB and Indeed Tokyo, with the addition of team sponsors Phaze Ventures, Spark Labs and REMY Robotics.

VTB, the largest international bank based in Eastern Europe, continues to be an official partner of the Hello Programming Bootcamp series, adding further quality to the 3rd edition of the Hello Barcelona Programming Bootcamp by bringing their own participants, as well as by supporting top teams from around the world.

Indeed Tokyo is Japan's branch of the #1 employment website in the world, giving job seekers free access to millions of jobs from thousands of company websites and job boards. As they sponsor for the second year in a row, Indeed continues to offer the best job opportunities to the boot camp participants.

Wish good luck to all the participants!

There will be 8 problems, common for both division. Score distribution: 500 750 1250 1500 1750 2250 2750 3000.

The problems are prepared by me, Arterm and GlebsHP, with assistance from 300iq, ifsmirnov and vintage_Vlad_Makeev. Have fun!

Hey Codeforces!

I made a thing and I want to share it with the community.

We wanted to keep track of achievements and submissions in our team and using Codeforces status page is not really handy. Therefore, I introduce to you Team dashboard.

Here you can find some kind of a timeline for each member of your team, showing last submissions, contests and even blog posts on Codeforces.

Using this script is pretty easy, just specify up to 3 handles in the address, separated by semicolons (please check below). Also please keep in mind that this script was made in 3-4 hours, so there is almost certainly a handful of bugs. Also, the script asks a lot of queries to the Codeforces API, so sometimes not all requests are answered. You should wait a couple of seconds and try again.

Visit right now and bookmark your team:

http://weaselcrow.com/pro/cf/team/?h=Radewoosh;Errichto;kostka

You can also compare yourself with your archenemy:

http://weaselcrow.com/pro/cf/team/?h=kostka;olekluka

Upd: fixed some bugs, including incorrect places and no response if no one from the team submitted anything.

Upd2: fixed bug with blocked blogs.

Upd3: you can now request as many days as you want, adding d argument, for instance:

http://weaselcrow.com/pro/cf/team/?h=mnbvmar&d=60

Please use it carefully, as requesting too many days will probably timeout.

Upd4: added team rating, as calculated by Codeforces.

Upd5: added problem ratings.