Edu round rating changes aren’t applied yet, so I’m confused: for today’s Div2, will delta be calculated using our current visible rating, or some internal pre-contest snapshot?

Also, is it possible that Codeforces publishes today’s rating changes before yesterday’s Edu changes?
If anyone knows how CF handles this ordering, please comment.

The Setup

You: “Solve this problem.”
GPT: “writes 200 lines of perfectly formatted C++17 with descriptive variable names and a poetic docstring.”
You: “It’s WA on test 3.”
GPT: “Have you tried using long long?”

How GPT Thinks It Codes:

"I analyzed 10^8 lines of ICPC gold-medal solutions and learned optimal dynamic programming patterns."

How GPT Actually Codes:

"Let's just sort the array and pray."

Debugging with GPT

You: “It’s TLE.”
GPT: “Hmm, maybe use unordered_map.”
You: “Still TLE.”
GPT: “Then switch to map for more structure.”
You: “It’s slower.”
GPT: “At least it’s elegant.”

GPT’s Logic in Action

Test 1: Works.
Test 2: Works.
Test 3: Segmentation fault.
GPT: “That’s impossible. Theoretically flawless.”

Then it proudly explains:

"Maybe the problem statement is wrong."
— confidently, like a true Codeforces Div. 3 participant.

GPT and Data Structures

GPT loves unordered_set, unordered_map, vector, queue, and multiset for emotional comfort.
It has used segment tree exactly once — in a dream.
And it believes Fenwick trees are “for advanced users only.”

GPT’s Submission Timeline

1. Writes 100 lines of code.
2. Passes sample tests.
3. Claims it’s O(n log n).
4. Fails test 3.
5. Says: "Probably precision error."
6. Adds 1e-9.
7. Now fails test 1.

GPT’s Advice Section

“If it’s wrong, just use a different approach.”
“If it’s slow, try Python.”
“If it’s still wrong, add +1 or -1 somewhere.”
“Remember: debugging is just re-training your neural network manually.”

Final Verdict

Sure, GPT can code.
But until it: - forgets to clear a vector between test cases,
- gets WA because it used int instead of long long,
- overflows in style,
- and blames the system tests —

it’ll never be one of us.

GPT doesn’t panic at Pretest 3.
GPT doesn’t cry over -17 rating.
GPT doesn’t scream “IT WORKED LOCALLY.”

That’s why GPT may code…
but it’ll never compete.

This is a letter for 2147C - Rabbits

Dear Problem C,

You tricked me. Oh, how you tricked me.

At first, you looked so innocent, like a “just a little greedy” problem. I thought, “Sure, just sum things up, maybe pick the max or min, easy peasy.” My heart skipped a beat of confidence.

But no. You were lying in wait. Each greedy step I took, you laughed. Each DP attempt, you smirked. Test 1 was fine, Test 2 was fine… and then Test 3 hit me like a ton of bricks. WA. My rating evaporated. My confidence? Shattered.

You looked like an easy greedy. You felt like a greedy. But inside, you had hidden rules, tricky orderings, and subtle catches that made my brain twist in ways I didn’t know were possible. Every time I thought I had you figured out, I found another trap.

Still, I can’t hate you. You taught me patience, observation, and the subtle art of thinking one step further than what seems “obvious.” You were a cruel lover, yes, but a beautiful one.

Problem C, you’re like that high-maintenance crush:

• Appears simple at first glance

• Secretly demands precision and care

• Breaks my heart before giving any reward

• And once solved, gives pure joy

I didn’t get you fully today, but I’ll be back. Next time, with sharper eyes and maybe a little extra caffeine. One day, I’ll AC you gracefully, and we’ll laugh together about all the WAs you gave me.

Yours, A hopeful (but exhausted) contestant

How many of you fell in love and heartbreak with Problem C like I did?

Just kidding the contest was awesome.

Hello Codeforces!

I think many of us have felt this: you’re excited for a contest, but the timing ends up clashing with school, work, or just life. Some contests appear randomly, and it becomes hard to plan ahead.

That’s why I believe we need two things back on Codeforces:

Weekend contests – A lot of people (especially students and full-time workers) are only free on weekends Back when we had more contests on Saturdays/Sundays, participation was higher and the atmosphere felt much more “global” Many regions have weekdays packed with exams, jobs, or classes, so weekends are the sweet spot

A predictable schedule – Imagine if contests followed a fixed plan, for example:

• Sundays = Educational Rounds

• Fridays = Div. 2 rounds

• Once a month on Saturday = Div. 1+2 combined (Just an example)

There might be some contests outside the main schedule, But we can have a global schedule too!

Of course the exact schedule can be debated, but the idea is simple: consistency If people know in advance what day usually hosts which type of contest, it’s easier to manage time and avoid missing contests

I think both of these changes would make Codeforces even more fun and accessible

Questions for you all :

Do you prefer contests on weekends or weekdays?

What would be your ideal weekly/monthly schedule?

Maybe if this blog gets enough attention, the Codeforces team will consider experimenting with this idea

Please share your ideas in the comments!

UPD:

Some people raised a good point in the comments — a strict contest schedule might clash with someone’s weekly commitments To address this, I thought of an adaptive schedule:

• Every month, Codeforces could run a quick community vote on the contest timing.

• It would be guaranteed that two consecutive months can’t have the same timing (the schedule must change).

This way, even if a schedule doesn’t work for someone in one month, it won’t repeat the next month. Plus, we’d still keep random-time contests and virtual contests, so nobody is locked out completely.

I think this makes the idea more flexible while still keeping the benefit of planning ahead.

What do you think about a voting system?

Codeforces has a treasure trove of problems across many topics—whether it’s greedy algorithms, dynamic programming, data structures, or graph theory. I’m curious to know: what is your favorite topic?

And if you have a problem that represents that topic, please share it in the comments! If you include a link to the problem, don’t forget to write its name next to it.