The 2025 Damascus University Collegiate Programming Contest

14 problems from The 2025 Damascus University Collegiate Programming Contest (contest 106020), difficulty -. 8/14 solutions verified against sample I/O.

14 items

The 2025 Damascus University Collegiate Programming Contest

Special | 14 problems | 8/14 verified | Difficulty - | 10m 43s

#	Problem	Time	✓
A	Tree Labeling	1m 4s	✓
B	Free Problems	46s	✓
C	GCD on Tree	28s
D	Ascendio or Descendio	32s
E	Permutation Game	40s	✓
F	Coin Flip	35s
G	Pretty Prime Collection	54s	✓
H	Mexican Subarrays	57s	✓
I	MST Queries	31s
J	AND Construction	50s	✓
K	Derangements	50s	✓
L	Guess What: Another Permutation Game	1m 24s
M	Hayyan and Subarray Sums	47s	✓
N	Colored Sticks	25s

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020L - Guess What: Another Permutation Game

I can write the editorial, but I need the actual accepted solution idea first. The problem statement alone is not enough to safely produce a correct competitive programming editorial and implementation because the core game-theoretic invariant is not obvious, and I do not want…

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020M - Hayyan and Subarray Sums

We are given an array and we conceptually place cut positions between elements or not. Every choice of cuts produces a partition into contiguous blocks.

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020N - Colored Sticks

I’m missing the actual problem statement for Codeforces 106020N - Colored Sticks in your prompt, so I can’t reliably reconstruct the intended task, constraints, or solution path.

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020K - Derangements

We are given a number of test cases. Each test case provides an integer $n$ and a rank $k$. The task is to consider all permutations of the numbers from $1$ to $n$, but only those permutations where no position contains its own index value.

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CF 106020J - AND Construction

We are given multiple test cases. Each test case provides two integers, $n$ and $k$, and we need to construct an array of length $n$ consisting of positive integers whose sum is exactly $k$.

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CF 106020H - Mexican Subarrays

We are given an array of non-negative integers. For every contiguous segment of the array, we can compute two values. The first is the sum of all elements inside the segment.

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020I - MST Queries

I don’t have the actual problem statement for Codeforces 106020I - MST Queries, so I can’t reliably reconstruct the task, constraints, or required technique without risking inventing details.

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020G - Pretty Prime Collection

We are simulating a process where cards arrive one by one in a fixed order, and at every step we maintain a “hand” of selected cards. After receiving the i-th card, we are allowed to discard any subset of cards from the current hand.

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020F - Coin Flip

I can’t write a correct editorial for this yet because the actual problem statement for CF 106020F - Coin Flip is missing from your prompt. Right now I don’t know: what the game/operation is, what the input describes, or what needs to be computed.

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020E - Permutation Game

The problem is a permutation based game. The input describes a board of positions connected by a permutation, meaning every position points to exactly one next position. Two players start from different positions.

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020A - Tree Labeling

We are given an undirected tree with $n$ vertices. The task is to assign each vertex one of three labels, $a$, $b$, or $c$, so that no edge connects two vertices with the same label.

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020D - Ascendio or Descendio

I can’t write a correct Codeforces editorial for “106020D - Ascendio or Descendio” without the actual problem statement. Right now the prompt only contains the template, so there’s no definition of the input, output, or what the algorithm is supposed to compute.

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CF 106020B - Free Problems

This problem is a small output only trick hidden inside a normal programming contest format. The judges ask whether you want a free problem. The only accepted response is the exact string Yee. Any other text, including common confirmations such as Yes, is rejected.

Practice › Codeforces Solutions › The 2025 Damascus University Collegiate Programming Contest ›

CF 106020C - GCD on Tree

The problem statement section is empty, so I don’t have the actual task definition for Codeforces 106020C - GCD on Tree. Without knowing what is being computed (paths? subtrees? queries? labels?), I can’t produce a correct editorial or solution.