In this post, I am summarizing a list of highlighted problems with their corresponding categories.
Interval Questions
1462F - Клад из отрезков — Given a list of intervals and a query interval, count efficiently how many given intervals overlap with the query interval?
Math
1463B - Найти массив — Modify an array s.t. every element is divisor/multiple of its neighbor(s), while sum of element-wise difference is no more than half of original array sum.
One elegant solution
1450C2 - Крестики Нолики Errichto (сложная версия) — No 3 continuous horizontal / vertical grid cells under the same color.
More hints