Kotlin Heroes: Episode 8

Solutions for Kotlin Heroes: Episode 8 (contest 1571). 3/10 problems verified against sample I/O. Difficulty range: 800-3200.

10 items

Kotlin Heroes: Episode 8

Type: Kotlin | Problems: 10 | Verified: 3/10 | Rating range: 800-3200 | Time: 31m 12s

Problem Name Rating Tags Solve Time Verified
A Sequence of Comparisons 800 *special 1m 31s ✓
B Epic Novel 1300 *special, math 2m 58s ✗
C Rhyme 1800 *special, implementation 3m 21s ✗
D Sweepstake 1800 *special, brute-force, constructive-algorithms 1m 39s ✓
E Fix the String 1700 *special, bitmasks, dp 2m 37s ✓
F Kotlinforces 2000 *special, constructive-algorithms, dp 2m ✗
G A Battle Against a Dragon 2500 *special, data-structures, dp 1m 40s ✗
H Laser Beams 2900 *special, geometry, probabilities 4m 7s ✗
I Physical Examination 3200 *special, binary-search, data-structures 1m 57s ✗
J Two Railroads 3000 *special 9m 22s ✗
Practice › Codeforces Solutions › Kotlin Heroes: Episode 8 ›

Practice › Codeforces Solutions › Kotlin Heroes: Episode 8 ›

CF 1571J - Two Railroads

The problem is not a small implementation bug. The entire algorithmic approach is fundamentally wrong. Let's trace the sample that immediately disproves it: The proposed algorithm sees at least one '1', then only checks the first and last characters: - s[0] = ')' → flip needed…
codeforces competitive-programming *special Jun 10, 2026
Practice › Codeforces Solutions › Kotlin Heroes: Episode 8 ›

CF 1571H - Laser Beams

We are given a rectangular game level defined by its width a and height b. Inside the level are n enemies, each at a unique position (xi, yi).
codeforces competitive-programming *special geometry probabilities Jun 10, 2026
Practice › Codeforces Solutions › Kotlin Heroes: Episode 8 ›

CF 1571I - Physical Examination

We are given several test cases. Each test case describes a set of doctors, where each doctor is available only during a fixed integer time interval.
codeforces competitive-programming *special binary-search data-structures Jun 10, 2026
Practice › Codeforces Solutions › Kotlin Heroes: Episode 8 ›

CF 1571E - Fix the String

We are given a string of brackets s and a binary string a of length n-3. Each '1' in a imposes a constraint that the corresponding 4-character substring of s must be a valid regular bracket sequence.
codeforces competitive-programming *special bitmasks dp greedy Jun 10, 2026
Practice › Codeforces Solutions › Kotlin Heroes: Episode 8 ›

CF 1571F - Kotlinforces

We are asked to place a collection of “events,” where each event is not a single day but a whole arithmetic progression of days.
codeforces competitive-programming *special constructive-algorithms dp Jun 10, 2026
Practice › Codeforces Solutions › Kotlin Heroes: Episode 8 ›

CF 1571G - A Battle Against a Dragon

Codeforces 1571G: A Battle Against a Dragon
codeforces competitive-programming *special data-structures dp Jun 10, 2026
Practice › Codeforces Solutions › Kotlin Heroes: Episode 8 ›

CF 1571C - Rhyme

We are given several pairs of strings, each marked either as needing to rhyme or explicitly not rhyming. Two strings rhyme under a positive integer $k$ if their last $k$ characters are identical and each string has length at least $k$.
codeforces competitive-programming *special implementation Jun 10, 2026
Practice › Codeforces Solutions › Kotlin Heroes: Episode 8 ›

CF 1571D - Sweepstake

We are given a competition with n programmers and a survey of m spectators, each predicting who will finish first and last. You, as the first spectator, have submitted your prediction (f1, l1).
codeforces competitive-programming *special brute-force constructive-algorithms implementation math Jun 10, 2026
Practice › Codeforces Solutions › Kotlin Heroes: Episode 8 ›

CF 1571A - Sequence of Comparisons

We are given a sequence of relational signs between consecutive elements of an array, and we are asked to determine whether we can uniquely infer the relation between the first and the last element.
codeforces competitive-programming *special Jun 10, 2026