My website

There is a great problem on Kattis called It’s a Mod, Mod, Mod, Mod World with a short statement: given $p$, $q$, and $n$, find $\sum_{i = 1}^{n} \left[ (pi) \bmod q \right]$. [Read More]

Today I’ll show the randomized solution for the problem E. Game of the Year. To solve it, I used XOR hashing. [Read More]

Today I’ll show the solution to the problem Dating (you can solve this problem on other platforms, such as Codeforces, too). The problem asks you to count the number of pairs of different types with the same number along a specific simple path in a tree. [Read More]

I’ll show you how I ended up implementing a sparse Lazy Segment Tree to solve a problem. There is a problem on oj.uz called Monkey and Apple-trees that involves range updates and range queries, but there is a small issue: the constraints are too large to build a data structure... [Read More]

Today I’ll talk about a trick that I learned in the Maratona de Programação Brasil group that I call the $(x + y, x - y)$ trick. This trick rotates a 2D grid by 45° and enables you to answer queries involving Manhattan distances, because after applying this transformation to... [Read More]