2025 Xian Jiaotong University Programming Contest

15 problems from 2025 Xian Jiaotong University Programming Contest (contest 105937), difficulty -. 15/15 solutions verified against sample I/O.

15 items

2025 Xian Jiaotong University Programming Contest

Special | 15 problems | 15/15 verified | Difficulty - | 17m 13s

# Problem Rating Tags Accepted Time ✓
A Card Master 54s ✓
B Nobody Can Log In 50s ✓
C Quantum Mechanics 1m 1s ✓
D Symmetrical Isolation: The Battle of Black and White 1m 2s ✓
E Pythagorean Cup 1m 24s ✓
F Beat Verdict: Precision Strike 1m 31s ✓
G Primal Core Optimization: Attribute Balance 1m 19s ✓
H 9-Nine 1m 14s ✓
I Ori 1m 5s ✓
J Bastion 1m 3s ✓
K Seele Vollerei 1m 13s ✓
L Gros-Phi 1m 22s ✓
M History of Terra 56s ✓
N Kessoku Band 1m 23s ✓
O Discrete Logarithm 56s ✓
Practice › Codeforces Solutions › 2025 Xian Jiaotong University Programming Contest ›

CF 105937N - Kessoku Band

We are given a permutation of numbers from 1 to n, meaning every integer in this range appears exactly once and is arranged in some order along a line. Each operation gives us a segment [l, r] of this line.
codeforces competitive-programming Jun 22, 2026
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CF 105937L - Gros-Phi

Each game describes a set of timed targets on a line. Every target is a pair consisting of a time moment and a position on the line. Starting at time zero, Awa can choose any initial position and then move along the line with a fixed maximum speed.
codeforces competitive-programming Jun 22, 2026
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CF 105937O - Discrete Logarithm

We are given three integers $a$, $c$, and a prime modulus $p$. The task is to construct a large integer $b$ such that a specific congruence holds between two expressions built from these values.
codeforces competitive-programming Jun 22, 2026
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CF 105937K - Seele Vollerei

We are working with a rooted tree whose structure is fixed, but whose root can change over time. Each node stores a weight, initially zero. On top of this tree, we are given a sequence of pre-defined path updates.
codeforces competitive-programming Jun 22, 2026
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CF 105937I - Ori

We are given a tree, meaning a connected acyclic graph. Each vertex represents a “core”, and edges represent allowed moves between cores. We are allowed to construct a walk on this tree, where revisiting vertices is permitted.
codeforces competitive-programming Jun 22, 2026
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CF 105937J - Bastion

We are given a simple polygon described by its vertices in counterclockwise order. The polygon is non-degenerate, so edges only meet at endpoints, no three consecutive vertices are collinear, and it forms a proper closed shape.
codeforces competitive-programming Jun 22, 2026
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CF 105937G - Primal Core Optimization: Attribute Balance

We are given a collection of $N$ points in a 3-dimensional integer space. Each point represents a partner with three attributes $(S, F, E)$. The goal is to apply operations so that all points become identical, meaning every partner ends with exactly the same triple.
codeforces competitive-programming Jun 22, 2026
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CF 105937E - Pythagorean Cup

We are given a line of $n$ cups. Each cup starts in one of three states: empty, half full, or full. A full cup immediately overflows and effectively becomes empty, so after initialization only empty and half-full cups matter.
codeforces competitive-programming Jun 22, 2026
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CF 105937H - 9-Nine

We are given two very small binary grids, each of size 3 by 3. Think of the first grid as configuration A and the second as configuration B. Every cell is either 0 or 1. We are allowed to perform three kinds of operations.
codeforces competitive-programming Jun 22, 2026
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CF 105937D - Symmetrical Isolation: The Battle of Black and White

We are given a rectangular board of size $N times M$. Each cell is either already black or white. We are allowed to paint additional white cells black, but we are never allowed to repaint a black cell back to white.
codeforces competitive-programming Jun 22, 2026
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CF 105937C - Quantum Mechanics

We are given a quantum system consisting of $n$ qubits, and instead of a classical state like a bitstring, the system is described as a complex-valued vector of size $2^n$. Each index of this vector corresponds to one basis state, i.e., one binary string of length $n$.
codeforces competitive-programming Jun 22, 2026
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CF 105937A - Card Master

We are given a single round of a very simple card game where exactly three cards are drawn. Each card has an integer value between 1 and 13. The score for the round is normally just the sum of the three values.
codeforces competitive-programming Jun 22, 2026
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CF 105937M - History of Terra

We are given a permutation-like array, except the values are arbitrary distinct integers rather than a contiguous range.
codeforces competitive-programming Jun 21, 2026
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CF 105937F - Beat Verdict: Precision Strike

We are interacting with a hidden integer $x$ that always lies between $1$ and $n$. We cannot see $x$ directly. Instead, we are allowed to ask up to four questions of the form “is $y x$?
codeforces competitive-programming Jun 21, 2026
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CF 105937B - Nobody Can Log In

We are given several login passwords, one per team, and each password is just a string composed of printable characters like digits, uppercase and lowercase letters, underscores, and hyphens.
codeforces competitive-programming Jun 21, 2026