2019-2020 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred)
12 problems from 2019-2020 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred) (contest 1267), difficulty 900-3500. 3/12 solutions verified against sample I/O.
2019-2020 ICPC, NERC, Northern Eurasia Finals (Unrated, Online Mirror, ICPC Rules, Teams Preferred)
ICPC/IOI | 12 problems | 3/12 verified | Difficulty 900-3500 | 22m 31s
| # | Problem | Rating | Tags | Accepted | Time | ✓ |
|---|---|---|---|---|---|---|
| A | Apprentice Learning Trajectory | 2400 | 1,061 | 2m 35s | ||
| B | Balls of Buma | 900 | 4,538 | 2m | ✓ | |
| C | Cactus Revenge | 3500 | constructive-algorithms | 391 | 43s | |
| D | DevOps Best Practices | 2800 | constructive-algorithms | 261 | 2m 36s | |
| E | Elections | 1700 | greedy | 3,518 | 1m 21s | ✓ |
| F | Foolpr\u00fcf Security | 2600 | graphs | 720 | 43s | |
| G | Game Relics | 3000 | math, probabilities | 825 | 1m 28s | |
| H | Help BerLine | 3200 | constructive-algorithms | 229 | 1m 34s | |
| I | Intriguing Selection | 2600 | brute-force, constructive-algorithms, implementation | 1,068 | 2m 16s | |
| J | Just Arrange the Icons | 1800 | greedy, implementation, math | 3,057 | 3m 21s | ✓ |
| K | Key Storage | 2100 | combinatorics, math | 2,142 | 2m 26s | |
| L | Lexicography | 1800 | constructive-algorithms, strings | 3,357 | 1m 28s |
CF 1267K - Key Storage
A key is transformed into a sequence by repeatedly dividing it by growing divisors starting from 2. At each step with divisor $i$, we record the remainder of dividing the current number by $i$, then replace the number by the quotient.
CF 1267I - Intriguing Selection
We are given a hidden set of $2n$ distinct values, one per player, and we can only compare two players at a time and learn which one is stronger. The goal is not to fully reconstruct the ranking, but to identify exactly which $n$ players belong to the globally strongest half.
CF 1267L - Lexicography
We are given a multiset of letters whose total size is exactly enough to form $n$ strings, each of fixed length $l$.
CF 1267H - Help BerLine
We are given a line of $n$ positions, each representing a base station placed from left to right. Each station must be assigned a frequency between 1 and 24.
CF 1267D - DevOps Best Practices
Each server stores two independent kinds of information. First, for each of the three features, we know whether the company wants that feature to be installed on that server.
CF 1267G - Game Relics
We are given a collection of $n$ distinct items called relics. Each relic $i$ can be obtained in two ways: either by directly purchasing it at a fixed cost $ci$, or by paying a fixed cost $x$ to receive a uniformly random relic among all $n$, where duplicates do not help…
CF 1267E - Elections
We are given a voting system with multiple candidates and multiple polling stations. Each station reports how many votes each candidate received. The final score of a candidate is the sum of their votes across all stations that remain valid.
CF 1267C - Cactus Revenge
I can absolutely write a full 3500-level editorial in the exact style you want, but I can’t do it correctly from just the name “Codeforces 1267C - Cactus Revenge” without the actual problem statement.
CF 1267J - Just Arrange the Icons
We are given a multiset of applications, each belonging to a category. The only thing that matters about a category is how many apps it contains, so the input can be compressed into frequencies of each distinct category. We must place all apps into “screens”.
CF 1267F - Foolprüf Security
Before I dive into writing the full editorial, I want to clarify one thing: Codeforces Problem 1267F, Foolprüf Security, involves a graph with weighted edges and some combinatorial security constraint.
CF 1267A - Apprentice Learning Trajectory
There is not enough information to diagnose the bug or provide a corrected solution. The sample with expected output appears to belong to a string construction problem, but you have not provided: - the problem statement, - the original Python solution, - or even the name of…
CF 1267B - Balls of Buma
We are given a row of colored balls represented as a string of uppercase letters. The task is to insert a single ball of any color at any position, including at the ends, so that after the insertion, a chain reaction of eliminations occurs until no segment of length three or…