After the rating rollback, I got my new rating, and finally, I'm an IM!!!!!!!! YEAH!!!!!!!

In this blog, I will tell you about my journey to reaching this rating.

I was taught by a very excellent teacher: ChatGPT.

Every day, I asked my teacher to give me one problem rated 2400 or 2500, focusing a lot on problems that required clever observations. I practiced every day, just one problem a day.

And in the World Quant Round, Problem G was exactly the kind of problem I had spent so much time practicing. By using a persistent trie and figuring out how to calculate f(b) by finding common prefixes, I managed to solve Problem G.

In the AI era, I think you should not use AI to cheat, but you can use AI as your assistant, your brainstorming partner, or even your personal tutor.

In my opinion, with the help of AI, you have the potential to become a much stronger competitive programmer than previous generations. However, if you use AI in the wrong way, the exact opposite can happen.

Use AI to improve your thinking, not to replace it.

The round 3 of meta hacker cup has ended and I'm waiting to get the information of the Tshirt.

When will the sheet appear ? Thank you ^^

Why does it feel like there are fewer problem Math type on Codeforces lately? Because ChatGPT ???

I think I'm quite good at Mathematics, and I'm so bad at constructive algo, greedy. Because I think about the solution very slow. But I feel that the problem setter does not want to set up the Math problem like Combinatorics, Expected Value ..... Because Cheater and ChatGPT ?

I've tried to submit this problem : https://codeforces.me/contest/2131/problem/F

On first submission, I got wrong answer on test case 2

https://codeforces.me/contest/2131/submission/333744450

I just copied the test case and run on my local and it got the correct answer

After that, I submit another solution with fill sum[i] = sumDiff[i] = 0 and got wrong on test 4

https://codeforces.me/contest/2131/submission/333745044

And after that, I copied this code and resubmit again, and it got wrong on test 2

Is there a problem with the judge system ?

Hello everyone

I'm so sad because Topcoder was a part of my life but it's dying nowadays

Is there any plan to reborn Topcoder in future ?

Hello everyone, I have a very hard problem (in my opinion) in my country's contest. I need your help, thanks a lot

Given an array a with N (1 <= N <= 200000) elements (1 <= a[i] <= N). Count how many triples (i, j, k) with satisfies:

. 1 <= i < j < k <= N . for each value x in subarray [ i .. j ], x is appears in subarray [ j + 1 .. k ] and for each value y in subarray [ j + 1 .. k], y is appears in subarray [i .. j]

For an example

N = 7

a = [3 1 2 1 2 3 1]

Output is 4

There are 4 triples (i, j, k): (1, 3, 6), (1, 3, 7), (1, 4, 7), (2, 3, 5)

Hello Codeforces — ers,

I have this problem need to solve

Given an array a with N integers (1 <= N <= 500000)

Given Q queries (1 <= Q <= 100000), for each query, we have 2 integers L and R, we have to find the maximum value of a[x] + a[y] + a[z] with sastifies:

. L <= x < y < z <= R . y — x < z — y

Thanks a lot :D

Hello everyone,

I'm looking forward to some problems in competitive programming which used some calculus techniques (derivatives, integrals, ....).

Would you please show me some problem :D :D :D ? The solution maybe just use only calculus, not using some hard techniques like FFT. Thanks a lot :D

Hello Codeforces,

My sister implemented the solution for 279B — Books here:

https://ideone.com/uPow6L

And so amazing !!!! This solution is accepted. I've tried but cannot create the test case to prove this solution is wrong. Can you help me ? Or can you prove that this solution is correct

Thank you a lot for your help.