2025 ICPC, Chula Selection Contest

14 problems from 2025 ICPC, Chula Selection Contest (contest 106118), difficulty -. 13/14 solutions verified against sample I/O.

14 items

2025 ICPC, Chula Selection Contest

ICPC/IOI | 14 problems | 13/14 verified | Difficulty - | 12m 21s

# Problem Rating Tags Accepted Time ✓
A Arranging Teams 58s ✓
B Balloon Trip 1m 1s ✓
C CK Chang's Shopping Spree 43s ✓
D Demon on the Grid 46s ✓
E Exotic Array 51s ✓
F Flipping Pyramid 1m ✓
G Graph Game 31s
H Horse Racing 1m 3s ✓
I Illuminated Ray Cast 51s ✓
J Jinglebell 53s ✓
K King of Tic-Tac-Toe 50s ✓
L Label the Tree 55s ✓
M Mine 1m 19s ✓
N Nobita's Homework! Help Me Doraemon 40s ✓
Practice › Codeforces Solutions › 2025 ICPC, Chula Selection Contest ›

CF 106118C - CK Chang's Shopping Spree

We are given a list of gadget prices and an initial amount of money. The buying rule is restrictive: before purchasing any gadget, the current amount of money must be at least ten times the price of that gadget. After buying it, the money is reduced by the gadget’s price.
codeforces competitive-programming Jun 20, 2026
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CF 106118N - Nobita's Homework! Help Me Doraemon

We are given three arrays of length n. The first two arrays define the boundary of an n by n grid. The first column is filled directly from the array a, the first row is filled from the array b, and the top-left cell is shared between them.
codeforces competitive-programming Jun 20, 2026
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CF 106118L - Label the Tree

We are given a rooted tree where vertex 1 is the root, and every other vertex has a fixed parent. On this tree we consider permutations of the vertices, meaning every vertex label from 1 to n appears exactly once in some order.
codeforces competitive-programming Jun 20, 2026
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CF 106118H - Horse Racing

We are given a weighted grid where every cell has a non-negative difficulty value. Movement is allowed in four directions on adjacent cells. For each query, we are given a starting position and a small axis-aligned rectangle containing at most 100 cells.
codeforces competitive-programming Jun 20, 2026
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CF 106118D - Demon on the Grid

We are working on an infinite integer grid where each point can potentially be the hidden location of a target. We receive several clues, and each clue consists of a center point and a distance.
codeforces competitive-programming Jun 20, 2026
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CF 106118M - Mine

We are working on a hidden grid of size $R times C$, where some unknown cells contain mines. The exact number of mines is not given, and their positions are completely hidden.
codeforces competitive-programming Jun 19, 2026
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CF 106118K - King of Tic-Tac-Toe

We are given a 3 × 3 Tic-Tac-Toe board. Each cell contains either X, O, or .. The board is not guaranteed to be a valid state from a normal game, so the counts of X and O do not matter. Nobita gets a special power: he may place two O marks consecutively on any two empty cells.
codeforces competitive-programming Jun 19, 2026
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CF 106118J - Jinglebell

We are given a graph of locations. There is a special node labeled 0, which represents Doraemon’s workshop, and there are n other nodes representing houses. Each house is marked as either good or bad.
codeforces competitive-programming Jun 19, 2026
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CF 106118I - Illuminated Ray Cast

We are given a sequence of vertical poles placed at integer coordinates on a line, where pole i sits at position x = i and has height h[i].
codeforces competitive-programming Jun 19, 2026
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CF 106118F - Flipping Pyramid

We are working on an infinite triangular grid where each cell is a location you can stand on, and each move corresponds to “flipping” a rigid tetrahedron from one cell to an adjacent cell.
codeforces competitive-programming Jun 19, 2026
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CF 106118E - Exotic Array

We are given an array of length $n$, where every entry must be an integer between $1$ and $m$. Among all such arrays, we are asked to count those that satisfy a very rigid structural constraint involving values of the array acting like a function on indices.
codeforces competitive-programming Jun 19, 2026
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CF 106118G - Graph Game

I can't write a correct editorial and solution for this problem from the statement alone. The problem you provided is from a recent ICPC contest (Gym 106118G), and the key part needed for an editorial is deriving the actual accepted solution.
codeforces competitive-programming Jun 19, 2026
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CF 106118B - Balloon Trip

We are given a line of mountains, each with an initial height. A journey is defined as walking from index $l$ to $r$, always moving one step to the right, and paying the cost of each move as the absolute difference between consecutive heights.
codeforces competitive-programming Jun 19, 2026
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CF 106118A - Arranging Teams

We are given a fixed set of n players, each with a strength value. We must choose a single ordering of these players, and that ordering will be reused unchanged against m different opponent teams.
codeforces competitive-programming Jun 19, 2026