XXII Open Cup. Grand Prix of Seoul

13 problems from XXII Open Cup. Grand Prix of Seoul (contest 103855), difficulty -. 12/13 solutions verified against sample I/O.

13 items

XXII Open Cup. Grand Prix of Seoul

Special | 13 problems | 12/13 verified | Difficulty - | 11m 46s

# Problem Rating Tags Accepted Time ✓
A Factory Balls 50s ✓
B Distance Optimizing Triangulation 49s ✓
C UCP-Clustering 48s ✓
D Triple Sword Strike 49s ✓
E RPS Bubble Sort 48s ✓
F Stones 1 54s ✓
G Stones 2 52s ✓
H Beacon Towers 2m 4s
I Marbles 54s ✓
J Exam 41s ✓
K Board Game 49s ✓
L Make Different 48s ✓
M Short Question 40s ✓
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855M - Short Question

The problem starts with a sequence of numbers and asks us to compute a global expression over all pairs of elements. For each array that appears in the input, we are effectively aggregating a function that depends on pairwise differences between elements.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855H - Beacon Towers

Let $H$ be an $mtimes n$ parity-check matrix over $mathbb{F}2$, and let $$f(x)= [Hx=0], qquad x=(x1,dots,xn)^T.$$ Fix a variable order $x1,dots,xn$.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855L - Make Different

We are working on a circular arrangement of $N$ positions, each position carrying a label, most naturally interpreted as a binary type such as 0 or 1, or more generally two kinds of “buttons”.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855K - Board Game

We are given a game played on a grid-like structure where each state can be thought of as a rectangular region with two dimensions. Two players alternate moves, and each move modifies the current active region by effectively trimming it along its boundary.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855J - Exam

We are working on a grid where every cell contains a value, and we care about paths that move from the top-left corner to the bottom-right corner.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855I - Marbles

We are given a system that builds and manipulates collections of marbles, where each marble can be thought of as an atomic unit that may later be grouped into larger sets.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855G - Stones 2

We are working with a sequence of stones, each stone having a color and a value. The operation that generates contribution is not local to a single stone, but depends on a triple of indices $i < j < k$.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855F - Stones 1

We are given a sequence of stones arranged in a line, each stone having a color and a weight. The first structural observation is that consecutive stones of the same color can be compressed: within any maximal block of identical colors, only the maximum weight in that block…
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855D - Triple Sword Strike

We are given a set of weighted points on a grid. Each point represents a monster located at some coordinate $(x, y)$ and contributing some value (or implicitly one unit of value if weights are not explicitly stated in the statement variant).
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855E - RPS Bubble Sort

We are given a string formed from characters that can be compared in a fixed “Rock Paper Scissors” style cycle, but the important restriction is that the dynamics we simulate only meaningfully depend on how characters compare pairwise.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855A - Factory Balls

We are working with a system that has a fixed target configuration of colors over several regions, and a set of tools that can modify those colors. Each region can take one of several possible colors, and each tool changes colors in a structured way.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855B - Distance Optimizing Triangulation

We are given a configuration of chords drawn inside a convex polygon. Each chord connects two boundary vertices, and different chords may intersect each other inside the polygon.
codeforces competitive-programming Jul 2, 2026
Practice › Codeforces Solutions › XXII Open Cup. Grand Prix of Seoul ›

CF 103855C - UCP-Clustering

We are repeatedly taking two groups of points in the plane and transforming them into a new pair of groups using a deterministic geometric rule.
codeforces competitive-programming Jul 2, 2026