The 21st Southeast University Programming Contest (Summer)

14 problems from The 21st Southeast University Programming Contest (Summer) (contest 105895), difficulty -. 13/14 solutions verified against sample I/O.

14 items

The 21st Southeast University Programming Contest (Summer)

Special | 14 problems | 13/14 verified | Difficulty - | 17m 55s

# Problem Rating Tags Accepted Time ✓
A \u4e00\u5361\u901a 52s ✓
B Royale Bataille 5m 20s
C Kings Game (Easy Version) 56s ✓
D Kings Game (Hard Version) 1m 10s ✓
E \u5341\u516d\u884c\u8bd7 57s ✓
F Yuhina City 1m 12s ✓
G Syl \u548c\u5e8f\u5217\u64cd\u4f5c 46s ✓
H Syl \u548c\u7f8e\u4e3d\u6811 50s ✓
I So Far Away 1m 11s ✓
J MEX Should Be Same 1m 2s ✓
K LRU is Best? (Easy Version) 1m 1s ✓
L LRU is Best? (Hard Version) 1m 5s ✓
M \u732b\u5a18\u90e8\u7f72 46s ✓
N \u6df7\u6c8c\u6570\u5b57 47s ✓
Practice › Codeforces Solutions › The 21st Southeast University Programming Contest (Summer) ›

CF 105895B - Royale Bataille

Codeforces 105895B: Royale Bataille
codeforces competitive-programming Jun 21, 2026
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CF 105895N - 混沌数字

We are given a noisy black-and-white image represented as an $n times m$ grid of characters. Each cell is either 0 or 1, where 1 corresponds to a white pixel and 0 corresponds to a black pixel.
codeforces competitive-programming Jun 21, 2026
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CF 105895M - 猫娘部署

We are given a small grid, up to 8 by 8, where each cell is either allowed or forbidden. Allowed cells contain a cat and are marked with a character like Y, while forbidden cells are marked with N.
codeforces competitive-programming Jun 21, 2026
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CF 105895L - LRU is Best? (Hard Version)

We process a sequence of events where each event reveals a value and a profit structure. Alongside this sequence, we maintain a cache with limited capacity.
codeforces competitive-programming Jun 21, 2026
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CF 105895J - MEX Should Be Same

We are given a square grid of size $n times n$, where each cell contains an integer between $0$ and $n$. We are allowed to modify at most half of the cells in the grid, rounding down. Each modification replaces the current value with any integer in the same range.
codeforces competitive-programming Jun 21, 2026
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CF 105895I - So Far Away

We are given a fully connected graph on $n$ vertices, but the edge weights are not arbitrary. Each vertex $i$ has a value $ai$, and the weight of the edge between $i$ and $j$ is defined as $min(ai, aj)$.
codeforces competitive-programming Jun 21, 2026
Practice › Codeforces Solutions › The 21st Southeast University Programming Contest (Summer) ›

CF 105895H - Syl 和美丽树

We are asked to construct a tree on nodes labeled from 1 to n. The tree must be rooted at node 1, and the only thing that matters in all constraints is the distance from node 1 to every other node in that tree.
codeforces competitive-programming Jun 21, 2026
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CF 105895G - Syl 和序列操作

We are given a sequence of integers, and the goal is to make all elements equal using a specific operation. Each operation is performed by choosing an index $i$, and then choosing one of three effects. The first effect changes only $ai$ by increasing or decreasing it by 1.
codeforces competitive-programming Jun 21, 2026
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CF 105895E - 十六行诗

We are given a sequence of integers representing rhyme labels of poems generated line by line. We are allowed to delete any number of lines, but we are not allowed to reorder the remaining ones.
codeforces competitive-programming Jun 21, 2026
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CF 105895D - Kings Game (Hard Version)

We are given an array of positive integers. Each query focuses on a contiguous segment of this array, and for that segment we are allowed to pick any subsequence (not necessarily contiguous, but preserving order) to form a “game array”.
codeforces competitive-programming Jun 21, 2026
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CF 105895C - Kings Game (Easy Version)

We are given an array of positive integers, and many queries. Each query selects a contiguous segment of this array. For that segment, the two players effectively play a game on a chosen subsequence of its elements.
codeforces competitive-programming Jun 21, 2026
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CF 105895K - LRU is Best? (Easy Version)

We are given a fixed sequence of requests, and a small “cache” of size at most $m$, initially empty. As we scan the sequence from left to right, each element we encounter can either already be in the cache or not.
codeforces competitive-programming Jun 21, 2026
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CF 105895F - Yuhina City

We are given a connected weighted undirected graph representing a city. Some nodes are radiation sources, each source node has a radiation strength that spreads through the graph and decays linearly with shortest-path distance.
codeforces competitive-programming Jun 21, 2026
Practice › Codeforces Solutions › The 21st Southeast University Programming Contest (Summer) ›

CF 105895A - 一卡通

We are given a single 9-character string that represents a student ID issued by a university system. The task is to decide whether this ID follows a very specific structural rule. The format is fixed-length and divided into conceptual segments.
codeforces competitive-programming Jun 21, 2026