Codeforces Round 505 (rated, Div. 1 + Div. 2, based on VK Cup 2018 Final)
7 problems from Codeforces Round 505 (rated, Div. 1 + Div. 2, based on VK Cup 2018 Final) (contest 1025), difficulty 900-3200. 5/7 solutions verified against sample I/O.
Codeforces Round 505 (rated, Div. 1 + Div. 2, based on VK Cup 2018 Final)
Div. 1+2 | 7 problems | 5/7 verified | Difficulty 900-3200 | 26m 51s
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| A | Doggo Recoloring | 900 | implementation, sortings | 16,523 | 2m 13s | ✓ |
| B | Weakened Common Divisor | 1600 | brute-force, greedy, number-theory | 8,508 | 2m 43s | ✓ |
| C | Plasticine zebra | 1600 | constructive-algorithms, implementation | 6,491 | 5m 11s | |
| D | Recovering BST | 2100 | brute-force, dp, math | 4,118 | 3m 32s | ✓ |
| E | Colored Cubes | 2700 | constructive-algorithms, implementation, matrices | 619 | 5m 51s | ✓ |
| F | Disjoint Triangles | 2700 | geometry | 908 | 3m 18s | |
| G | Company Acquisitions | 3200 | constructive-algorithms, math | 864 | 4m 3s | ✓ |
CF 1025G - Company Acquisitions
We are given a system of startups arranged into a structure where some startups are already “active” and others are “acquired” and attached to exactly one active startup.
CF 1025E - Colored Cubes
We are given an $n times n$ grid and $m$ identical-sized cubes, each having a unique color. Each cube starts on a distinct cell, and each also has a target cell where it must eventually be placed.
CF 1025F - Disjoint Triangles
We are given a set of points in the plane with two strong structural guarantees: no two points coincide and no three are collinear. From these points we can form triangles by choosing any three vertices, and every such triangle is non-degenerate.
CF 1025D - Recovering BST
We are given a sorted list of distinct integers, and we want to build a binary search tree using exactly these values as node keys.
CF 1025C - Plasticine zebra
We are given a binary string made of two symbols, black and white, and we want to extract a long contiguous segment that alternates perfectly between the two colors.
CF 1025B - Weakened Common Divisor
We are given a collection of pairs of integers. From each pair, we are allowed to pick exactly one number. After making one choice per pair, we obtain a multiset of selected values. The task is to find an integer greater than 1 that divides every chosen value.
CF 1025A - Doggo Recoloring
We are given a string representing the colors of a line of puppies, where each character is a color from 'a' to 'z'. The goal is to determine whether we can transform this string so that all characters become the same, using a very specific operation.