2020-2021 ICPC NERC (NEERC), North-Western Russia Regional Contest (Northern Subregionals)
14 problems from 2020-2021 ICPC NERC (NEERC), North-Western Russia Regional Contest (Northern Subregionals) (contest 104013), difficulty -. 14/14 solutions verified against sample I/O.
2020-2021 ICPC NERC (NEERC), North-Western Russia Regional Contest (Northern Subregionals)
ICPC/IOI | 14 problems | 14/14 verified | Difficulty - | 15m 12s
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| A | Archivist | 2m 34s | ✓ | |||
| B | Bicycle | 43s | ✓ | |||
| C | Corrupted Sort | 56s | ✓ | |||
| D | Display | 51s | ✓ | |||
| E | Easy Compare-and-Set | 48s | ✓ | |||
| F | Futures Market Trends | 43s | ✓ | |||
| G | Grammar Path | 50s | ✓ | |||
| H | Heroes of Coin Flipping | 53s | ✓ | |||
| I | Integer Square | 2m 8s | ✓ | |||
| J | Joint Password Storage | 1m 14s | ✓ | |||
| K | Keys and Locks Boolean Logic | 51s | ✓ | |||
| L | Lost Permutation | 1m 3s | ✓ | |||
| M | Mind the Gap | 45s | ✓ | |||
| N | Nunchucks Shop | 53s | ✓ |
CF 104013N - Nunchucks Shop
We are working with a set of binary “sticks”, each stick being a sequence of length n where every position is either quartz or onyx. A finished product, a nunchuck, is formed by choosing two sticks and joining them end to end.
CF 104013L - Lost Permutation
We are given an unknown permutation π on n elements, but we are not allowed to see it directly. Instead, we can feed the system any permutation f, and we receive back a transformed permutation g defined by conjugation through π, meaning that every value is relabeled by π…
CF 104013M - Mind the Gap
We are given a set of distinct integers representing cards held by different players. There is also an initial pile that starts with a single card of value 0.
CF 104013I - Integer Square
We are given a single year in the range from 1995 to 2019. Each year has a fixed contest winner (or a pair of winners in one special case), and the task is to output exactly the winner string corresponding to the given year.
CF 104013J - Joint Password Storage
We are given several passwords, each a short string of length at most 50 made of digits and English letters. For every password, we must construct a collection of strings, all of the same length as the password, such that if we take the bitwise XOR of ASCII codes column by…
CF 104013K - Keys and Locks Boolean Logic
We are given a boolean formula built from variables a through h and the operators not, and, and or with standard precedence rules. The formula defines which subsets of variables are considered valid. Each variable corresponds to a band member who may or may not be present.
CF 104013H - Heroes of Coin Flipping
We are dealing with a complete knockout tournament with $2^k$ participants, where every match is a fair coin flip between two players.
CF 104013G - Grammar Path
We are given two separate structures that must interact: a context-free grammar in Chomsky Normal Form and a directed graph whose edges are labeled by lowercase letters.
CF 104013A - Archivist
We are given a single year in the range from 1995 to 2019. Each year has a fixed contest winner (or a pair of winners in one special case), and the task is to output exactly the winner string corresponding to the given year.
CF 104013E - Easy Compare-and-Set
We are given a collection of operations on a single integer variable that starts with value c. Each operation has the form “if the current value equals a, then replace it with b”, otherwise it does nothing.
CF 104013F - Futures Market Trends
We are given a sequence of daily oil prices and we want to inspect every contiguous subarray of length at least three. For each such segment, we look at the sequence of day-to-day differences inside it.
CF 104013C - Corrupted Sort
We are given a hidden array of length $n$, containing a permutation of numbers from $1$ to $n$. We cannot see the array directly. Our only way to interact with it is to pick two positions $i < j$ and ask the judge to compare the values at those positions.
CF 104013D - Display
We are given a library of pixel fonts where each printable character is represented as a fixed bitmap of size $w times h$. Each bitmap is a grid of and ., where means the pixel is lit and . means it is dark.
CF 104013B - Bicycle
A cyclist is choosing between two monthly bike rental plans, and we need to compute the total cost of each plan over a fixed month. Each day, the cyclist uses the bike for a total of T minutes.