Basic tools for competitive programmers. From simple mathematics to data structures implementations to test case generators.
For most of the topics 2 files exist:
1) The first file that is meant to provide you with a simple snippet that you can include in your code and thus use the function(s) and or struct(s) that it provides.
2) The second has the "_with_explanation" suffix in its name and it is meant to give detailed comments on the implemenation.