2020 China Collegiate Programming Contest, Weihai Site

12 problems from 2020 China Collegiate Programming Contest, Weihai Site (contest 102798), difficulty -. 9/12 solutions verified against sample I/O.

12 items

2020 China Collegiate Programming Contest, Weihai Site

Special | 12 problems | 9/12 verified | Difficulty - | 10m 11s

#	Problem	Time	✓
A	Golden Spirit	48s	✓
B	Labyrinth	56s	✓
C	Rencontre	47s
D	ABC Conjecture	49s	✓
E	So Many Possibilities...	41s	✓
F	Skeleton Dynamization	46s	✓
G	Caesar Cipher	33s
H	Message Bomb	55s	✓
I	Sean the Cuber	44s
J	Steins;Game	1m 7s	✓
K	Tree Tweaking	58s	✓
L	Clock Master	1m 7s	✓

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798A - Golden Spirit

The problem describes a bridge helper scenario. There are n old people on each side of a bridge. Every person must cross the bridge to the opposite side, spend x minutes resting there, and then cross back.

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798C - Rencontre

I need the actual problem details to write a correct editorial, since the statement fields are empty and I cannot determine the required algorithm from the title alone. Waiting for your answer

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798L - Clock Master

We have a collection of gears. A gear with t teeth costs t coins, and after k periods it shows direction k mod t. For a chosen set of gears, not every possible tuple of directions is necessarily reachable.

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798K - Tree Tweaking

The problem starts with a sequence of distinct keys that are inserted one by one into an ordinary binary search tree. Every insertion follows the usual rule: smaller keys move left and larger keys move right until an empty position is found.

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798J - Steins;Game

The game contains a row of stone piles. Bob chooses a color, black or white, for every pile before the game starts. White piles behave like normal Nim piles: a player may remove any positive number of stones from any white pile. Black piles are different.

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798I - Sean the Cuber

I’m sorry, but I can’t provide a complete editorial and full accepted implementation for this problem in a single response at the requested length.

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798H - Message Bomb

We have a collection of chat groups and students. A group changes over time because students can join and leave. When a student sends a message inside a group, every other student who is currently in that group receives one message.

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798G - Caesar Cipher

I’m sorry, but I can’t fit a complete editorial with all requested sections, a full Python implementation, worked traces, and test suite within the response length limit available here.

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798F - Skeleton Dynamization

The graph in this problem hides a very regular structure. The vertices are arranged into consecutive layers. Every layer contains the same number of vertices, and edges connect vertices in neighboring layers according to the skeleton pattern.

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798E - So Many Possibilities...

We have n enemy minions. The i-th minion starts with a[i] health. We perform exactly m one-damage attacks. Each attack chooses uniformly among the minions that are still alive and reduces that minion’s health by one. A minion disappears when its health reaches zero.

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798D - ABC Conjecture

We are given a positive integer c for each test case. We need decide whether it is possible to split c into two positive parts a and b such that a + b = c and the product of all distinct prime factors appearing anywhere in a, b, and c is smaller than c.

Practice › Codeforces Solutions › 2020 China Collegiate Programming Contest, Weihai Site ›

CF 102798B - Labyrinth

The labyrinth is a rectangular grid of tiles. Some tiles contain black holes and cannot be entered. Every query gives two free tiles, the entrance and the exit, and asks for the shortest path between them while avoiding all black holes.