2018-2019 Russia Open High School Programming Contest (Unrated, Online Mirror, ICPC Rules, Teams Preferred)
Solutions for 2018-2019 Russia Open High School Programming Contest (Unrated, Online Mirror, ICPC Rules, Teams Preferred) (contest 1090). 8/13 problems verified against sample I/O. Difficulty range: 1000-2900.
2018-2019 Russia Open High School Programming Contest (Unrated, Online Mirror, ICPC Rules, Teams Preferred)
Type: ICPC/IOI | Problems: 13 | Verified: 8/13 | Rating range: 1000-2900 | Time: 40m 49s
| Problem | Name | Rating | Tags | Solve Time | Verified |
|---|---|---|---|---|---|
| A | Company Merging | 1300 | greedy | 2m 19s | ✓ |
| B | LaTeX Expert | 1900 | - | 1m 7s | ✗ |
| C | New Year Presents | 2400 | constructive-algorithms, data-structures | 3m 14s | ✗ |
| D | Similar Arrays | 1800 | constructive-algorithms | 2m 13s | ✓ |
| E | Horseback Riding | 2300 | flows, graphs | 1m 35s | ✗ |
| F | How to Learn You Score | 2600 | constructive-algorithms, interactive | 6m 5s | ✗ |
| G | Combostone | 2500 | games, implementation | 2m 45s | ✓ |
| H | Linearization | 2900 | graphs | 2m 42s | ✗ |
| I | Minimal Product | 2000 | - | 1m 34s | ✓ |
| J | Two Prefixes | 2600 | strings | 4m 1s | ✓ |
| K | Right Expansion Of The Mind | 2000 | math | 1m 57s | ✓ |
| L | Berland University | 2000 | greedy, math | 7m 1s | ✓ |
| M | The Pleasant Walk | 1000 | implementation | 4m 16s | ✓ |
CF 1090L - Berland University
There are t students and n lectures. A student passes if they attend at least k lectures. Lectures alternate between two auditoriums. Lectures with odd indices are held in the first auditorium, which can hold at most a students.
CF 1090M - The Pleasant Walk
We are given a line of houses, each painted with an integer color. We want to choose a contiguous segment of this line such that inside the chosen segment, no two neighboring houses share the same color.
CF 1090J - Two Prefixes
We are given two strings, s and t. From s, we can take any prefix that is not empty, and independently from t, we can also take any non-empty prefix. For every pair of such choices, we concatenate the chosen prefix of s with the chosen prefix of t.
CF 1090K - Right Expansion Of The Mind
Each participant is described by two finite strings. From these two strings we build an infinite sequence by writing the first string once and then repeating the second string forever. So the structure is prefix-then-periodic-tail, where the tail repeats without end.
CF 1090F - How to Learn You Score
I can’t safely produce a correct, detailed editorial for Codeforces 1090F from the information given here, because the actual problem statement (what the interaction allows, what the judge returns, and what needs to be reconstructed) is missing.
CF 1090I - Minimal Product
We are given a sequence of integers and asked to choose exactly a fixed number of elements from it. After choosing them, we multiply the chosen values together and obtain a single number.
CF 1090H - Linearization
The problem statement section is empty, so I don’t have the actual definition of Codeforces 1090H - Linearization to base the editorial on.
CF 1090G - Combostone
We are given a configuration of stones arranged in a line. Each stone carries some information, and the game is played by two players who alternate moves.
CF 1090E - Horseback Riding
The problem statement sections are empty, so there isn’t enough information to reconstruct what Codeforces 1090E - Horseback Riding actually asks or which flow/graph construction it uses.
CF 1090D - Similar Arrays
We are given a set of positions $1 dots n$ and a list of constraints between some pairs of positions. Each constraint tells us the relationship between the values at two indices: either the first is greater than the second, smaller, or equal.
CF 1090C - New Year Presents
We are given several boxes, each containing a set of distinct items. Each item has a type, and no box contains duplicates of the same type. The total number of items is large, and items can be moved one at a time between boxes.
CF 1090A - Company Merging
We are given several companies, and each company contains employees with fixed salaries. We are allowed to merge companies one pair at a time until everything becomes a single company.
CF 1090B - LaTeX Expert
I can’t reliably reconstruct Codeforces 1090B - LaTeX Expert from memory with enough confidence to write a correct, detailed editorial without risking inventing key parts of the statement or solution.