Hello MikeMirzayanov and Codeforces administration,

I am writing this post from my friend's account because my own Codeforces account, vikramgupta, has been disabled and I am currently unable to access it or create a blog post from my account.

When I try to access my account, Codeforces shows:

"User is disabled by administrators."

I have checked the email address associated with my account, [email protected], and I have not received any email explaining the reason for the disablement.

I am therefore sincerely requesting a manual review of my account and my recent contest activity.

I also want to be completely honest about something that may be relevant to this situation.

During the contest, after I had already developed the solutions and written the majority of the code myself, I used ChatGPT for limited coding assistance. Specifically, I used it to help complete/formulate a particular function and to help fix an error in code that I had already written. I did not use it to obtain the main algorithms or problem-solving ideas.

The observations, approaches and overall logic for the problems were developed by me. However, after thinking about the rules more carefully, I understand that using AI for coding assistance during a contest may itself have been outside the permitted rules.

I sincerely apologize for this mistake.

I genuinely did not intend to gain an unfair advantage or undermine the contest. I had already spent time understanding the problems and developing the solutions myself, and I made the mistake of using AI at the implementation/debugging stage. I now understand that the rules have to apply equally to everyone, regardless of how much or how little AI assistance was used.

I am genuinely sorry for this.

I want to make clear that I am not trying to hide this or make excuses for it. If this use of AI was the reason for the action against my account, I understand why the administration would take it seriously. I accept responsibility for my mistake.

At the same time, I would be extremely grateful if my complete contest activity could be manually reviewed and if the administration could consider the circumstances of my case.

I can explain the approaches I used for the problems in detail:

A: I first looked at the number of 1s in the array and realized that the condition depends only on whether the number of 1s is at least half of n. I simply counted the ones and compared 2 * ones with n. If it was enough, I printed Bessie; otherwise, Elsie.

B: I first found the possible range of k. If k is smaller than n or greater than 2n-1, I understood that construction is impossible, so I printed -1. For the valid range, I constructed the matrix by first placing consecutive values in the required positions and then filling the remaining positions with unused consecutive values while maintaining the required condition.

C1: I converted the condition into intervals. For every k, the values affected by a[k] form an interval from k*a[k] to k*(a[k]+1)-1. I marked these intervals using a difference array instead of processing every element separately. After taking the prefix sum, the positions that were not covered by any interval were exactly the values I needed.

C2: For the harder version, I extended the interval idea from C1, but now I needed to count valid sets instead of only finding one. I marked the positions that were forced using the difference array and also kept the constraints coming from the smaller intervals. Then I used DP with prefix sums to count the possible ways efficiently. I maintained the latest required position so that invalid choices could be removed from the DP range. The final count was calculated modulo 1e9+7.

D: This problem required me to maintain several groups while processing the permutation in reverse order. I used a Fenwick Tree to quickly calculate the sum of values in a range and a set to maintain the starting positions of the current groups. For every new element, I checked whether it could belong to the previous group or had to start a new one. After adding it, I also merged neighbouring groups whenever their accumulated sum was sufficient. The number of remaining groups directly gave the answer for that position.

E: For this one, I first observed that the final arrangement can be represented by two arithmetic progressions: one starting from 0 and increasing by some difference D, and another starting from the maximum value and decreasing by the same D. I realized that there are only a couple of possible values for D, which can be obtained from the first and last elements. I generated the two sequences for each candidate, sorted them, and checked whether they exactly matched the given array. For every valid candidate, I multiplied by the factorial terms representing the possible arrangements.

I am mentioning these approaches because I want to be completely transparent that I understood and developed the underlying problem-solving approaches myself, even though I made the mistake of using limited AI assistance during the final implementation/debugging stage.

If required, I am completely willing to explain any of these solutions in detail, provide my source code, show my local development environment, or answer questions about any part of my submissions.

I also noticed that several submissions in my recent activity are shown as Skipped, following earlier accepted submissions.

I do not want to make assumptions about why this happened. I would sincerely appreciate it if the administration could tell me whether these submissions, my AI usage, or any other activity resulted in the account action.

I am willing to cooperate fully with any review.

I understand that Codeforces has to protect the fairness and integrity of its contests. I respect that completely.

I am truly sorry for using AI assistance during the contest, even though it was limited to the implementation/debugging stage. I should have avoided it completely, and I promise that I will not use AI assistance during Codeforces contests again.

I have spent a lot of time building my Codeforces profile, solving problems, participating in contests, and improving my rating. My rating, solved problems, contest history, and other Codeforces activity are also connected to my competitive-programming profiles and records elsewhere. Losing access to the account would therefore be a very significant loss for me.

I am not asking the administration to ignore the rules or overlook a genuine violation. I am only sincerely asking for my case to be reviewed and, if possible, for my account to be restored.

If there is a penalty or any appropriate action that the administration believes is necessary, I will respect the decision. I would simply be extremely grateful for an opportunity to have my account reviewed rather than permanently lose the account and all the work associated with it.

I sincerely apologize to the Codeforces administration and community. I understand my mistake now, I regret it, and I promise not to repeat it.

Please consider reviewing @vikramgupta and, if possible, restoring my account.

Codeforces handle: @vikramgupta Registered email: [email protected]

Thank you very much for taking the time to read this and consider my request.

I am genuinely sorry and sincerely request one opportunity to correct my mistake.