Hey CodeForces!

Thank you for your warm support for my online lectures! Now it's winter vacation in Russia, next semester will start in February. I want to use this time to try some topics which were not included in the main course (mainly because it's already too big).

The first lecture will be on Saturday at 17:00 MSK, I will talk about this classical work by R. E. Tarjan explaining the $$$α(m, n)$$$ time complexity of Union-Find data structure.

If you're not familiar with Union-Find data structure, you can watch my lecture, or take this lesson in EDU.

See you!

UPD. There is a Div2 round tomorrow, so I moved the lecture to Saturday.