SWERC 2022-2023 - Online Mirror (Unrated, ICPC Rules, Teams Preferred)
Solutions for SWERC 2022-2023 - Online Mirror (Unrated, ICPC Rules, Teams Preferred) (contest 1776). 4/14 problems verified against sample I/O. Difficulty range: 800-3500.
SWERC 2022-2023 - Online Mirror (Unrated, ICPC Rules, Teams Preferred)
Type: ICPC/IOI | Problems: 14 | Verified: 4/14 | Rating range: 800-3500 | Time: 26m 25s
| Problem | Name | Rating | Tags | Solve Time | Verified |
|---|---|---|---|---|---|
| A | Walking Boy | 800 | greedy | 1m 17s | ✓ |
| B | Vittorio Plays with LEGO Bricks | 2200 | dp, geometry | 1m 38s | ✗ |
| C | Library game | 2500 | games, greedy, interactive | 1m 21s | ✗ |
| D | Teamwork | 2800 | constructive-algorithms, greedy, math | 1m 51s | ✗ |
| E | Crossing the Railways | 3500 | data-structures, dp | 1m 51s | ✗ |
| F | Train Splitting | 1700 | constructive-algorithms, graphs, greedy | 2m | ✗ |
| G | Another Wine Tasting Event | 2100 | combinatorics, constructive-algorithms, math | 1m 4s | ✓ |
| H | Beppa and SwerChat | 1300 | two-pointers | 2m 13s | ✓ |
| I | Spinach Pizza | 2500 | games, geometry, greedy | 1m 19s | ✗ |
| J | Italian Data Centers | 2500 | graphs, shortest-paths | 2m 32s | ✗ |
| K | Uniform Chemistry | 3200 | dp, math | 2m 12s | ✗ |
| L | Controllers | 1500 | binary-search, math | 3m 41s | ✗ |
| M | Parmigiana With Seafood | 3000 | binary-search, dp, greedy | 2m 20s | ✗ |
| N | Count Permutations | 3500 | math | 1m 6s | ✓ |
CF 1776M - Parmigiana With Seafood
This is a Type B (prove inequality) problem, not Type C. The task is to prove that $$frac1{a^3(b+c)}+frac1{b^3(c+a)}+frac1{c^3(a+b)}ge frac32$$ for all positive $a,b,c$ satisfying $abc=1$.
CF 1776L - Controllers
We are asked to determine whether a player can reach exactly zero score after a sequence of game rounds, given a controller with two buttons labeled with arbitrary positive integers.
CF 1776N - Count Permutations
We are asked to count the number of permutations of the numbers from 1 to $n$ that satisfy a chain of inequalities described by a string of length $n-1$. Each character of the string is either < or .
CF 1776K - Uniform Chemistry
Each researcher starts with a chemical labeled by an integer between $1$ and $n-1$. Every year they upgrade their current chemical: if someone currently holds value $a$, they replace it with a uniformly random integer from the interval $(a, n]$.
CF 1776J - Italian Data Centers
Codeforces 1776J: Italian Data Centers
CF 1776H - Beppa and SwerChat
The list shown by SwerChat is ordered by recency. The member who was online most recently appears first, the second most recent appears second, and so on. At 9:00, Beppa records an ordering a. At 22:00, she records another ordering b.
CF 1776I - Spinach Pizza
We are given a strictly convex polygon with labeled vertices in counterclockwise order. Each move consists of choosing one currently unused vertex.
CF 1776F - Train Splitting
We are given a connected undirected graph. Every edge must be assigned to a company. Suppose company c owns all edges colored c. The coloring must satisfy two conditions. The first condition says that no single company is allowed to own a connected spanning network.
CF 1776G - Another Wine Tasting Event
We are given a binary string of length $2n-1$, where each position represents a bottle of wine, either white or red. From this fixed sequence, we need to assign $n$ critics to $n$ distinct segments of the array.
CF 1776E - Crossing the Railways
We are asked to simulate a person, Isona, crossing a set of parallel railway tracks from one platform to another, while avoiding trains. The crossing is straight and perpendicular to the railways.
CF 1776D - Teamwork
We are asked to schedule a team of three people to solve a set of problems with three difficulty levels: easy, medium, and hard. Each problem has a fixed duration depending on its difficulty: easy takes 2 units of time, medium 3 units, and hard 4 units.
CF 1776A - Walking Boy
The task asks us to determine whether it is possible for the judge to have walked Boy, her dog, at least twice during a single day given a timeline of messages. Each walk takes exactly 120 minutes, cannot overlap another walk, and the judge never sends messages during a walk.
CF 1776B - Vittorio Plays with LEGO Bricks
We are asked to place a set of LEGO Duplo bricks on a 1D line along the x-axis, with the constraint that each brick occupies a 2×2 square on the ground and has height 1.
CF 1776C - Library game
We are playing a sequential game on a line of labeled sections, each section representing a distinct subject. Each day, one of two players chooses a contiguous interval of sections, constrained by a fixed length coming from a multiset of available “passes”.