Osijek Competitive Programming Camp, Fall 2023. Day 6: Estonian Contest (The 2nd Universal Cup. Stage 19: Estonia)
10 problems from Osijek Competitive Programming Camp, Fall 2023. Day 6: Estonian Contest (The 2nd Universal Cup. Stage 19: Estonia) (contest 104925), difficulty -. 8/10 solutions verified against sample I/O.
Osijek Competitive Programming Camp, Fall 2023. Day 6: Estonian Contest (The 2nd Universal Cup. Stage 19: Estonia)
Special | 10 problems | 8/10 verified | Difficulty - | 10m 47s
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| A | Alternating Paths | 3m 56s | ✓ | |||
| B | Binary Sequence | 44s | ✓ | |||
| C | Yet Another Balanced Coloring Problem | 40s | ✓ | |||
| D | Filesystem | 30s | ||||
| E | Freshman's Dream | 59s | ✓ | |||
| F | When Anton Saw This Task He Reacted With 😩 | 45s | ✓ | |||
| G | LCA Counting | 1m 6s | ✓ | |||
| H | Minimum Cost Flow\u00b2 | 35s | ✓ | |||
| I | Rebellious Edge | 38s | ||||
| J | 'Ello, and What Are You After, Then? | 54s | ✓ |
CF 104925A - Alternating Paths
We are given an undirected connected graph where each edge must be assigned one of two colors, red or blue. After coloring, we want a strong reachability property: between every pair of vertices, there must exist a walk that alternates colors on consecutive edges.
CF 104925J - 'Ello, and What Are You After, Then?
We are repeatedly interacting with a collection of “task providers”, called slayer masters. Each master has a fixed list of tasks. A task has a frequency weight, a duration, and an XP rate per minute.
CF 104925I - Rebellious Edge
We are given a directed graph on vertices labeled from 1 to n, with a distinguished root at vertex 1. The task is to choose a set of directed edges that forms a spanning arborescence rooted at 1, meaning every vertex is reachable from 1, and every vertex except the root has…
CF 104925G - LCA Counting
We are given a rooted tree with root fixed at node 1, and we are told which vertices are leaves of this tree. From this set of leaves, we will choose exactly k of them, for every k from 1 up to the total number of leaves.
CF 104925H - Minimum Cost Flow²
We are given a directed graph with a designated source node and sink node. Instead of choosing a discrete set of paths or integer flows, we assign a real-valued flow to every edge, possibly negative, as long as flow conservation holds at every vertex and the net flow from…
CF 104925F - When Anton Saw This Task He Reacted With 😩
We are given a rooted binary tree where each internal node combines the results of its two children using a fixed operation: the vector cross product in three dimensions.
CF 104925E - Freshman's Dream
We are given a number $n$, and for each test we must either construct two positive integers $a$ and $b$ (both below $2^{60}$) or report that no such pair exists. The required condition mixes addition and bitwise XOR in a way that forces carries and bit cancellations to interact.
CF 104925D - Filesystem
We are given a set of files, each file having two independent total orders defined on it. One order is by file name, the other is by creation date. The file names order is fixed and already represented by indices from 1 to n.
CF 104925B - Binary Sequence
The sequence starts from a single binary digit string and evolves by repeatedly describing the previous string in terms of runs of identical digits. Each run is converted into two parts: the length of the run and the digit being repeated.
CF 104925C - Yet Another Balanced Coloring Problem
We are given two rooted trees that share the same set of leaf vertices labeled from 1 to k. Every other vertex is an internal node.