I released an atom plugin, codeblue, a week ago which was only supporting python to test and run code. You can also submit the solution from within the atom.

BUT NOW IT SUPPORTS C and C++ too. Go ahead and download the package from the install tab of atom settings.

To learn more about its features and capabilities: https://codeforces.net/blog/entry/81753

Github repo: https://github.com/blueedgetechno/codeblue

watch the gif: https://gifyu.com/image/cGq8

Download my atom package for codeforces ,codeblue.

source: https://github.com/blueedgetechno/codeblue

Features

• Fetch and load code forces contest details

• Automatically create an environment for the contest including working files

• Run code with official sample cases of any particular problem

• Compare your output with expected output in an elegant manner

• Get your code verdicts like OK, Wrong answer, TLE, MLE, Runtime error, Queue, Hacked

• Submit your code from your favorite text editor

• Get your official standing of the live contest

• Play minigames while you wait for the contest

It would have been alot helpful if there will be a contestId parameter in contest.list method of codeforces API. It takes some time to load and filter essential contest information from https://codeforces.net/api/contest.list call.