VOJ-ranking-bot

A Discord bot which helps calculate ranking in a Codeforces group. It also plots various data like rating distributions, user submission statistics.

Features

Get suitable problem for training

Ranking

• Create group ranking:

Graph

• Plot rating history:

• Plot training history (number of submission per day):

• Plot training history by number of submission:

• Get list of solved problems:

• Plot training history by number of solved problem per problem category:

• Plot rating distributions of a group:

Other

• For VNOI: get codeforces link of a VOJ problem
• Some git commands to update the bot.

Installation

Clone this repository

• python pip install -r requirements
• Base on file .env-example, create file .env and fill all the data: bot token, account codeforces (for crawling submission), codeforces group id, access link to Mongo db atlas.

How to use

• Create a discord bot, add it to your discord server.
• Then use python main.py to run the bot. Remember to edit data in .env.
• Use ;voj help to see list command

Warning for large group

Codeforces stopped displaying the status for large groups. So this bot will not working for large group.

Crawler

Because there is no APIs to get submissions data directly, I have to get it myself by crawling the Submission page of Codeforces group.

You can see the crawler in /service/SubmissionCrawler.py.

Issues

This is some sort of issues and I'm not figure out how to solve it:

• What if a user change their handle? Since Codeforces allow users change their handle once time per year.
• What if we rejudge a problem? If we rejudge a problem, all the submission information about that problem have to delete and re-crawl but I don't know how to do since there is no APIs.
• What if we rename a problem?

Q&A

• Question: How rank is calculated? Answer: Each problem has a point, equal to 80 / (40 + x) with x is number of users got accepted in that problem. If a user submit to a problem and receive a accepted verdict, they will earn all the problem's point. If they receive a partial score, they will earn partial_score * problem_point / 100 points.

Note

• There is some commands required Admin role. If you're not bot's owner, you will need Admin role to use those commands.
• You can update the bot (get new commit from this repository) by using ;voj git_pull command. Then you can use ;voj restart to restart the bot (you don't need to run it again, it's very useful since I'm running the bot in a VPS).