IOI 2021

There are n boxes, each with capacity c[i]. There are q operations, where operation j adds v[j] candies to all boxes in range [l[j], r[j]]. If v[j] > 0, candies are added (capped at capacity). If v[j] < 0, candies are...

Given two strings a and b of equal length over the alphabet \ A, T, C\, answer queries: for a given substring range [l, r], what is the minimum number of swaps to transform a[l..r] into b[l..r]? If impossible, return -1.

There are n dungeons (indexed 0 to n-1) and a final dungeon n. Each dungeon i has: s[i]: opponent strength p[i]: strength gain if you lose w[i]: next dungeon if you win (w[i] > i) l[i]: next dungeon if you lose If you...

Given n rooms and m bidirectional corridors. Each room i contains a key of type r[i]. Each corridor j connects rooms u[j] and v[j] and requires a key of type c[j] to traverse. Starting from room i, you pick up the key...

There are n fountains at positions (x[i], y[i]) where all coordinates are even. Two fountains are adjacent if they differ by exactly 2 in one coordinate and are equal in the other. Build roads between adjacent fountai...

You have m = 100 registers, each containing b = 2000 bits. Register 0 initially contains n values, each k bits wide, packed consecutively. The remaining bits are 0. You must output the sorted values (or just the minim...