Hello Codeforces! 🌎 👋

First, take a look at the last sentence of this screenshot:

According to the setters, they would be upset if someone dropped a problem after the h hacking phase. 😅 But I did drop 3 problems ! 🤯 Problems C, D, and E were all hacked. 💔

I'm now wondering what m3tr0 and his friends will do now 🤔?

This blog is just for fun. 😁

By the way, has anyone dropped more than that after a system test? 🤔 I’m talking about those who were confident in their solutions, not those who submitted without proof.

Hello everyone.

Does anyone have an idea of what is just going on here? I just dropped 430 rating.

Yesterday, I was solving this problem 1175D - Array Splitting from Educational Codeforces Round 66 (Rated for Div. 2). Initially, it was rated as 1900, and after reading it, I spent around 15 minutes with no idea. I was about to give up, but for some reason, I decided to attempt an approach using prefix sums. After outlining my idea on my board, I quickly realized the solution was simple. I implemented it, and after 35 minutes from the start, I got it accepted on the first submission.

Is it a good performance to solve a 1400-rated problem in 35 minutes?

Has recalling a problem you've already solved ever made a difference in a CP event like winning?

Hello Codeforces ☀️☀️☀️.

It has been one year now since I joined Codeforces 15th February 2023 . Today is 16th February 2024 ✨.

Some great memories of contests:

• Educational Codeforces Round 143 (Rated for Div. 2) This was my first contest where i solved 1 problem at 01:57 (3 min before the end of the contest)

• Codeforces Round 871 (Div. 4) On this contest, I reached Pupil rating for the first time after almost three months since I started solving 6 problems.

• Codeforces Round 899 (Div. 2) On this contest, I reached the Specialist rating for the first time after seven months since I started. Note that initially after that contest, my rating was 1399,i even posted a blog about that. And it was days after with rollback that I got an extra +2, bringing me to 1401.

• Educational Codeforces Round 158 (Rated for Div. 2) And as you know, everything that goes up needs to come down :). A few contests later, I was back to Newbie on this contest , and my rating was 1181.

• Codeforces Round 914 (Div. 2) Some days after that fall, I had one of my best performances ever, if it is not the best ever, on this contest when I solved 5 problems in that Div2 and getting a +140.

Short story about that contest:

I still don't know if i'm truly Specialist but we will know that in upcoming weeks.

Feel free to ask your questions in the comment !!

When do you think I will get to expert?

• April

• June

• After

Update : 22 March 2024

I'm now Expert 🔥 💥 🎁 🎯 💯 🌈 ⭐ 🎈 🤩 🤧 😴 😳 😭 😈

How does it feel to be an Expert ? 😈

Oooh I love it and I hate it at the same time ...... Yeah, this makes me happy and also indifferent at the same time. In fact when you finally achieve something you were willing for so long you suddenly ask yourself so that's how it feel ?

You all were wrong 5 weeks ago when I asked about the time I will reach Expert

It took me 1 year and 1 month to achieve that 🎯. I can still remember when I started I didn't know what was dfs and how to code it. In today Div2C I was able to do it quicky bringing me to that which seems like impossible 6 months ago !!

Problem statement

Given a graph with $$$n$$$ nodes and $$$m$$$ edges,

• Find a path that starts at a node (the node is not specified).
• Visit each edge at least once.
• End the path at the starting node.
• Minimize the total cost of the tour.

Input

• The number of nodes $$$n$$$ : $$$2 \leq n \leq 20$$$
• The number of edges $$$m$$$ : $$$1 \leq m \leq 100$$$.
• For each edge, provide the source node, destination node, and the cost associated with that edge.

Output

Output the minimum cost of a tour that satisfies the conditions mentioned above.

Note

The path must visit each edge at least once (meaning you can pass the number of time you want), and the tour must end at the starting node.

Can the problem be solved using :

• $$$dp$$$ with bitmask?
• min cost max flow?

If you have any solution feel free to comment on it. Thanks!!!

You are given an integer $$$n \leq 10^9$$$. Your task is to compute the number of ways $$$n$$$ can be expressed as the sum of even numbers. Since the answer could be very large, compute it modulo $$$10^9 + 7$$$.

Time limit : 1s

Sample : $$$n = 8$$$

$$$8 = 6 + 2$$$

$$$8 = 4 + 4$$$

$$$8 = 4 + 2 + 2$$$

$$$8 = 2 + 2 + 2 + 2$$$

Therefore for $$$n = 8$$$ the answer would be $$$4$$$

Do anyone know how to solve this problem? Comment on the solution

UPDATE Thanks to Wielomian and estoy-re-sebado for sharing some ways to solve this problem

Hello Codeforces ☀️☀️☀️

We are glad to invite you to participate in this weekend contest which will take place on [contest_time:490250]

You will be given 12 problems and 2 hours and 15 minutes to solve them.

All the problems are written and prepared by LiquidFun and based on an onsite competition hosted at FSR Informatik.

Note that the problems difficulty are easy so all newbies and pupils are invited to participate in this contest.

Specialists and above should be able to finish the contest and are also invited to participate for fun.

Have a nice contest ✨ !!

UPDATE 1 You can now register for the contest via this link

UPDATE 2 Starting soon. Get ready

UPDATE 3

Congratulations to the winners!

Congratulations to the first solvers as well!

I would like to thank one more time LiquidFun for giving us access to his problems without which we would not have been able to organize this contest.

Feel free to comment your impressions on the contest so we can consider them for the next contest !!

UPDATE 4

You can find the solutions to the problems and all the materials used for this contest here.

We will be happy if you can give a star to the repository.

I have just finished a virtual participation of this Div 3.

At the end i have seen something strange to me.

There are three friends (i mean they are cp teammates) that were close on my friend scoreboard so i decided to have a look at their progression. Personally FBI always inspire me to keep going as he started as a newbie ans is currently Candidate Master.

Here are they and their graph progression :

FBI

Pa_sha

SashaT9

Another amazing thing is that their current level is so close. I'm still wandering if there are other friends that started cp at the same time and have such progression together.

If you know another persons feel free to comment their name so that we can have a look at their graph. It may inspire some persons.

Rating have just been recalculated.

I'm feeling quite sad because I missed getting to see a specialist for the first time ever by just one point I scored +110 instead of the required +111

Hello Codeforces!

I have been doing cp for 8 months now and even if i feel like i have learned a lot of things my rating is not showing the same thing. Moreover It seems like i have the same level as i started back to February.

Some months ago i decided to start doing one Div3 virtual every day and upsolve the problems i wasn't able to do. Strange thing i most of the time perform good but during it but in real contest it not the same.

Last time during Educational Codeforces Round 154 (Rated for Div. 2) i end up solving only one problem but few minutes (5 to 10 min) after the end i was able to solve 1861C - Queries for the Array and i found that my solution for 1861B - Two Binary Strings was good but i loop from 0 to n-2 instead of n-1. That would have make it 3 problems and something like specialist performance since most of them were not able to solve that C

Here is graph of solve problem.

If anyone have an advice that can help me improve feel free to state it in the comment. Thanks

Hello codeforces. Can anyone tell why this approach 217040454 in not working for this problem 1203B - Equal Rectangles?

Hello, Codeforces community! We have some brilliant coders among us who consistently produce clean, readable, and elegant code during contests. These individuals not only amaze us with their problem-solving skills but also set a great example for code readability. Today, I invite you all to help us recognize and acknowledge these Codeforces Clean Code Champions by listing their usernames below.

How to Contribute:

• Simply comment below with the Codeforces username of a coder you believe writes clean and readable code during contests.

• Briefly mention what sets their coding style apart and why you find their solutions impressive.

• Feel free to nominate multiple coders who deserve recognition for their clean code practices.

Let's come together to create a valuable list of Codeforces Clean Code Champions that can serve as inspiration and learning material for the entire community. Happy nominating, and may we all strive for cleaner and more readable code!