2021-2022 ICPC, NERC, Southern and Volga Russian Regional Contest (problems intersect with Educational Codeforces Round 117)
14 problems from 2021-2022 ICPC, NERC, Southern and Volga Russian Regional Contest (problems intersect with Educational Codeforces Round 117) (contest 103430), difficulty -. 13/14 solutions verified against sample I/O.
2021-2022 ICPC, NERC, Southern and Volga Russian Regional Contest (problems intersect with Educational Codeforces Round 117)
Educational | 14 problems | 13/14 verified | Difficulty - | 12m 30s
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| A | Armor and Weapons | 44s | ✓ | |||
| B | Special Permutation | 41s | ✓ | |||
| C | Athletes | 48s | ✓ | |||
| D | Max Sum Array | 39s | ✓ | |||
| E | Request Throttling | 2m 20s | ||||
| F | X-Magic Pair | 42s | ✓ | |||
| G | Chat Ban | 53s | ✓ | |||
| H | Messages | 46s | ✓ | |||
| I | Tetris | 50s | ✓ | |||
| J | Bongcloud Opening | 46s | ✓ | |||
| K | Ice Cream Van | 49s | ✓ | |||
| L | Smash the Trash | 44s | ✓ | |||
| M | Distance | 1m 4s | ✓ | |||
| N | Haiku | 44s | ✓ |
CF 103430E - Request Throttling
Let $q$ be a primitive $m$th root of unity and let $$N = n1 + cdots + nt.$$ Write each index in base $m$ form $$ni = m ai + ri,qquad 0 le ri < m,$$ and define $$A = a1 + cdots + at,qquad R = r1 + cdots + rt,$$ so that $N = mA + R$.
CF 103430C - Athletes
We are given two independent groups of athletes, one group for sport A and one group for sport B. Each athlete has a numerical skill value, and every athlete must stay in their own sport unless we explicitly decide to “swap” them, meaning they compete in the other sport…
CF 103430N - Haiku
We are given three separate text lines, and each line must be checked against a target vowel count pattern. The pattern is fixed as 5 vowels in the first line, 7 vowels in the second line, and 5 vowels in the third line.
CF 103430M - Distance
We are given two points on a 2D grid, call them A and B. Each point has integer coordinates, and distances are measured in the standard geometric sense.
CF 103430L - Smash the Trash
We are given a sequence of locations arranged in a line. Each location initially contains some amount of trash. There is a cleaning process that involves choosing a number of workers, and these workers move through the locations in order, cleaning trash at each one.
CF 103430K - Ice Cream Van
We are given a system of positions indexed from 1 to n. Each position has a rule that determines where we move next: from i we either move one step forward to i + 1, or we make a larger jump to i + k[i]. Which of the two happens depends on a changing parameter x.
CF 103430J - Bongcloud Opening
The problem describes a system where a player starts with an initial rating and plays a sequence of matches. Each match is not just a simple increment or decrement, but depends on a chosen “opening” that affects how the rating evolves across subsequent games.
CF 103430A - Armor and Weapons
We are effectively navigating a grid of states, where each state represents owning a particular armor type and a particular weapon type.
CF 103430I - Tetris
We are given a collection of segments, each segment representing a Tetris piece placed on a row. Each piece occupies a continuous interval on a number line, from a left endpoint $Li$ to a right endpoint $Ri$, and carries a value $ci$.
CF 103430H - Messages
We are given a set of students. Each student is associated with a specific message index and a limit value that controls how reliably they will read a pinned message depending on how many total messages are pinned.
CF 103430G - Chat Ban
The process in this problem is easiest to think of as a sequence that grows step by step, where each step corresponds to sending one more message in a chat, and each message contributes a certain number of “emotes” depending on its position in the sequence.
CF 103430F - X-Magic Pair
We are given a pair of positive integers, and we repeatedly apply an operation that always acts on the larger value. The only move allowed is to replace the larger number by its difference with the smaller one. The process continues until one of the numbers becomes zero.
CF 103430D - Max Sum Array
We are given an array where each value can be thought of as a type, and each type has a frequency. The task is to construct a permutation of the array that maximizes a certain global score that depends on how many times equal values interact across positions.
CF 103430B - Special Permutation
We are working with a permutation construction problem where two special values, say a and b, define a directional constraint over positions.