Integrating with Codeforces API: A Guide for Developers

This article was originally published on our website https://isab.run. The Medium version offers the same in-depth content and insights.

Codeforces is a popular platform for competitive programming and coding challenges. It is widely used by programmers, developers, and students around the world to sharpen their skills and test their abilities against others. With its vast collection of problems, solutions, and user-submitted code, Codeforces is an excellent resource for anyone looking to improve their coding skills.

To get the most out of Codeforces, developers can leverage the Codeforces API to access the platform’s data programmatically. In this article, we will walk through the process of integrating with the Codeforces API and show you how to use it to retrieve information about users, contests, and problems.

Before we begin, it’s important to note that you will need an API key to access the Codeforces API. You can obtain an API key by visiting the API registration page on the Codeforces website. Once you have your API key, you can start making requests to the API.

The first step in integrating with the Codeforces API is to make a request to retrieve information about a user. To do this, you will need to make a GET request to the following URL:

https://codeforces.com/api/user.info?handles={handle}&apiKey={apiKey}

Where {handle} is the username of the user you want to retrieve information about and {apiKey} is your API key.

The API will return a JSON object containing information about the user, including their name, rating, and number of solved problems. You can then use this information to display user statistics on your website or application.

Next, you can use the Codeforces API to retrieve information about a contest. To do this, you will need to make a GET request to the following URL:

https://codeforces.com/api/contest.list?gym={gym}&apiKey={apiKey}

Where {gym} is a Boolean value indicating whether you want to retrieve information about official contests (gym=false) or gym contests (gym=true) and {apiKey} is your API key.

The API will return a JSON object containing information about the contest, including the contest name, start time, and end time. You can then use this information to display contest schedules on your website or application.

Finally, you can use the API to retrieve submission data, including the user’s handle, problem name, and submission status (e.g. accepted or wrong answer). This allows you to keep track of your users’ performance on Codeforces and offer them personalized feedback and support.

To integrate with the Codeforces API, you will need to create an API key. This can be done by logging into your Codeforces account, going to the API registration page, and clicking on the “Register” button. Once you have your API key, you can use it to make API calls to the Codeforces API.

To make API calls, you can use a programming language of your choice. For example, in Python, you can use the requests library to make HTTP requests to the API. Here is an example of how to retrieve the list of upcoming contests using the Codeforces API:

import requests

api_key = 'YOUR_API_KEY'
url = 'https://codeforces.com/api/contest.list'

response = requests.get(url, params={'gym': False, 'apiKey': api_key})

if response.status_code == 200:
    contests = response.json()['result']
    for contest in contests:
        print(contest['name'])
else:
    print('Error:', response.status_code)

In this example, we are sending a GET request to the https://codeforces.com/api/contest.list endpoint with the parameters gym set to False and apiKey set to our API key. The API will then return a JSON object containing a list of contests, and we are iterating through the list and printing the name of each contest.

It’s important to note that the Codeforces API has some limitations on the number of requests that can be made per day. So, it’s important to use the API judiciously and cache data whenever possible.

In conclusion, integrating with the Codeforces API allows you to retrieve a wealth of information about contests and submissions, which can be used to enhance the functionality of your website or application. With a little bit of code, you can easily display contest schedules, track users’ performance, and offer personalized feedback and support.

Additionally, the Codeforces API also allows for the retrieval of information about users, such as their ratings, ranks, and submissions. This can be useful for creating leaderboards, tracking progress, and providing personalized recommendations.

One thing to keep in mind when working with the Codeforces API is that it is rate-limited. This means that you are limited to a certain number of requests per minute, so it is important to be mindful of this when designing your application or website.

Overall, the Codeforces API is a powerful tool that can be used to enhance the functionality of your website or application and provide a better experience for your users. With a little bit of coding, you can easily retrieve valuable information and offer a wide range of features, such as contest schedules, leaderboards, and personalized feedback.