Kotlin Heroes: Episode 10

Solutions for Kotlin Heroes: Episode 10 (contest 1958). 7/10 problems verified against sample I/O. Difficulty range: 1100-3200.

10 items

Kotlin Heroes: Episode 10

Type: Kotlin | Problems: 10 | Verified: 7/10 | Rating range: 1100-3200 | Time: 11m 13s

Problem	Name	Rating	Tags	Solve Time	Verified
A	1-3-5	1100	*special, dp	47s	✓
B	Clock in the Pool	1400	*special, math	44s	✓
C	Firewood	1500	*special	1m	✓
D	Staircase	1600	*special	1m 14s	✗
E	Yet Another Permutation Constructive	1900	*special, constructive-algorithms	1m 4s	✗
F	Narrow Paths	2000	*special, combinatorics	1m 12s	✓
G	Observation Towers	2400	*special	1m 18s	✓
H	Composite Spells	2600	*special, dp	1m 34s	✓
I	Equal Trees	3100	*special, graphs, meet-in-the-middle	1m 8s	✗
J	Necromancer	3200	*special	1m 12s	✓

Practice › Codeforces Solutions › Kotlin Heroes: Episode 10 ›

CF 1958A - 1-3-5

We are asked to construct an exact sum using coins of values 1, 3, and 5. For each target amount n, we want to pay exactly n using any number of 3 and 5 coins, and we are only forced to use 1-coins when it becomes unavoidable.

Practice › Codeforces Solutions › Kotlin Heroes: Episode 10 ›

CF 1958B - Clock in the Pool

The clock is not a normal continuous display, it behaves like a repeating cycle of three states. Every cycle has length $3k$ seconds.

Practice › Codeforces Solutions › Kotlin Heroes: Episode 10 ›

CF 1958C - Firewood

Monocarp has a single log of wood that weighs exactly $2^n$ grams. He needs to split this log into pieces such that he can assemble exactly $k$ grams of wood for today's fireplace, leaving the remaining $2^n-k$ grams for tomorrow.

Practice › Codeforces Solutions › Kotlin Heroes: Episode 10 ›

CF 1958D - Staircase

We are given a line of staircase steps, each step either needing repair or already fine. If a step is fine, it behaves like a zero in the input. If it is broken, it carries a positive cost value that represents its repair difficulty. The repair process is constrained by days.

Practice › Codeforces Solutions › Kotlin Heroes: Episode 10 ›

CF 1958E - Yet Another Permutation Constructive

We are given a permutation, which is just an ordering of the numbers from 1 to n. We repeatedly apply a transformation that removes elements which are strictly smaller than at least one of their immediate neighbors.

Practice › Codeforces Solutions › Kotlin Heroes: Episode 10 ›

CF 1958F - Narrow Paths

We are working on a very constrained grid: only two rows and a large number of columns. The start is the top-left cell, and the goal is the bottom-right cell.

Practice › Codeforces Solutions › Kotlin Heroes: Episode 10 ›

CF 1958G - Observation Towers

Each observation tower sits at a fixed position on a number line from 1 to n and has a current viewing radius given by its height. A tower can “see” every integer point whose distance from its position does not exceed its height.

Practice › Codeforces Solutions › Kotlin Heroes: Episode 10 ›

CF 1958H - Composite Spells

We are given a spell system that behaves like a program written in a very restricted language. The first part of the system is a list of basic operations, each of which either increases or decreases a monster’s health by a fixed integer.

Practice › Codeforces Solutions › Kotlin Heroes: Episode 10 ›

CF 1958I - Equal Trees

We are given two rooted trees on the same labeled vertex set from 1 to n, both rooted at 1. Each tree is described by its parent array, so every node knows its immediate parent except the root.

Practice › Codeforces Solutions › Kotlin Heroes: Episode 10 ›

CF 1958J - Necromancer

We are simulating a very specific combat process on a fixed line of monsters, and answering many independent queries on subsegments of that line.