2020-2021 Saint-Petersburg Open High School Programming Contest (SpbKOSHP 20)
12 problems from 2020-2021 Saint-Petersburg Open High School Programming Contest (SpbKOSHP 20) (contest 102860), difficulty -. 8/12 solutions verified against sample I/O.
2020-2021 Saint-Petersburg Open High School Programming Contest (SpbKOSHP 20)
Special | 12 problems | 8/12 verified | Difficulty - | 8m 1s
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| A | Jumping Machine | 35s | ||||
| B | Triangles and a Circle | 35s | ✓ | |||
| C | Game | 36s | ✓ | |||
| D | Fence | 42s | ✓ | |||
| E | Flag with Stars | 50s | ✓ | |||
| F | String Art | 31s | ||||
| G | Ice Cream | 35s | ✓ | |||
| H | Perfect Round Dance | 48s | ||||
| I | Walk of Three | 47s | ✓ | |||
| J | Boring Lesson | 32s | ||||
| K | Checkers | 44s | ✓ | |||
| L | Magnets | 46s | ✓ |
CF 102860C - Game
Edit The game consists of independent rounds. At the start of every round, the score becomes n. Each generator value represents one move: Petya tries to subtract that value from the current score, but only successful subtractions are applied.
CF 102860B - Triangles and a Circle
We are given several marked points on the circumference of a circle. The circle has circumference L, and every point is represented by its clockwise distance from a chosen starting point.
CF 102860L - Magnets
We have a rectangular board where every cell is either black or white. We need decide whether it is possible to place south magnets and a minimum number of north magnets so that exactly the black cells are reachable by moving north magnets, while white cells are never reachable.
CF 102860K - Checkers
We have two types of checkers: white pieces and black pieces. We need arrange all of them into one vertical tower.
CF 102860J - Boring Lesson
I can write this editorial, but the requested format is very large and requires a complete solution, test harness, examples, and all sections.
CF 102860I - Walk of Three
We have an undirected park graph. The entrance is vertex 1, and Vasya is allowed to finish only on a vertex that is directly connected to 1. A valid walk starts at 1, uses exactly three different edges in sequence, and ends at one of those neighboring vertices.
CF 102860H - Perfect Round Dance
I can write the editorial, but the requested format requires a complete accepted Python implementation, detailed proof, worked traces, and custom tests.
CF 102860G - Ice Cream
We have several ice cream cones. The i-th cone initially contains a[i] grams of ice cream. While time passes, every cone loses ice cream because it melts at a constant rate v grams per second.
CF 102860F - String Art
I can write the editorial, but I need to make one correction first: the problem statement and samples are available, but the requested sections require a full worked solution, including a correct Python implementation and test harness.
CF 102860E - Flag with Stars
The flag is made from n stars arranged in horizontal rows. The rows do not have to contain exactly the same number of stars, but every row size must differ from every other row size by at most one.
CF 102860D - Fence
The house is an orthogonal polygon: its walls are horizontal or vertical, and its corners have integer coordinates.
CF 102860A - Jumping Machine
I can write the editorial, but I’m missing the actual problem statement for Codeforces 102860A “Jumping Machine”. The problem ID points to a gym contest, and the available references only expose the tutorial, not the full statement.