2022 Huazhong University of Science and Technology Freshmen Cup

14 problems from 2022 Huazhong University of Science and Technology Freshmen Cup (contest 103973), difficulty -. 12/14 solutions verified against sample I/O.

14 items

2022 Huazhong University of Science and Technology Freshmen Cup

Special | 14 problems | 12/14 verified | Difficulty - | 14m 16s

# Problem Rating Tags Accepted Time ✓
A Monster Killer 49s ✓
B Subset Counting 51s ✓
C Roll the Circle 47s ✓
D Random 55s ✓
E Merging Stones 58s ✓
F String Problem 1m 10s ✓
G Math Learning 50s ✓
H Substrings 1m 11s
I Photos 47s ✓
J Two Kings 50s ✓
K The Grandstand 44s ✓
L Phigros 2m 1s
M Walk Alone's Conjecture 1m 5s ✓
N Coloring 1m 18s ✓
Practice › Codeforces Solutions › 2022 Huazhong University of Science and Technology Freshmen Cup ›

CF 103973L - Phigros

Let $G=(V,E)$ be a finite graph. A set $Dsubseteq V$ is dominating when every vertex $vin Vsetminus D$ has a neighbor in $D$. A kernel $Ksubseteq V$ is an independent set such that every vertex $vin Vsetminus K$ has a neighbor in $K$. Let $K$ be a kernel of $G$.
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CF 103973N - Coloring

We are given a graph that is already guaranteed to be bipartite. This means the vertices can be split into two groups such that every edge connects vertices from different groups. On top of this structure, some vertices are already assigned colors: red, blue, or uncolored.
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CF 103973M - Walk Alone's Conjecture

We are given many independent values of $n$. For each $n$, we must construct two integers $x$ and $y$ such that $y - x = n$, while also ensuring that $x$ and $y$ have the same number of prime factors when counted with multiplicity.
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CF 103973K - The Grandstand

We are given a grid made of n × m cells. Each cell is either empty or marked as red. Our task is to decide whether the red cells form exactly one of four predefined geometric patterns named H, U, S, or T.
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CF 103973J - Two Kings

We are given two kings on an infinite chessboard. One king belongs to Walk Alone (white) and the other to Salix Leaf (black). They alternate moves starting with white, and each king moves like a standard chess king, meaning it can step to any of the eight neighboring squares.
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CF 103973H - Substrings

Let $G=(V,E)$ be a graph. A set $Ksubseteq V$ is a kernel of $G$ when it is independent and every vertex $vin Vsetminus K$ has a neighbor in $K$. A set $Dsubseteq V$ is a dominating set when every vertex $vin Vsetminus D$ has a neighbor in $D$.
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CF 103973I - Photos

We are given a tree of buildings. Each building is a node and each road is an edge, and the structure guarantees there is exactly one simple path between any two nodes. Two people start simultaneously: one starts at node $a$, the other starts at node $b$.
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CF 103973F - String Problem

We are given two strings, a source string s and a target string t. From s, we want to pick a contiguous segment, and we want this segment to match a prefix of t after we are allowed to modify t in a very specific way: we may choose a length k and reverse the first k characters…
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CF 103973G - Math Learning

We are given a rooted tree of formulas. Each node represents a formula, and each formula has an energy cost that is paid when Walk Alone has to “learn” it again.
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CF 103973E - Merging Stones

We are given several piles of stones, each pile having a positive integer size. We repeatedly merge two existing piles until only one pile remains.
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CF 103973D - Random

We are given a bitwise transformation applied to a fixed number of bits. An unsigned integer x is represented using exactly k bits, so every value lies in the range from 0 to 2^k - 1. We are also given an array of operations.
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CF 103973B - Subset Counting

We are given a set of consecutive integers starting from 1 up to a large upper bound of the form $nm + k$. From this set, we consider all possible subsets. For each subset, we compute the sum of its elements, then reduce that sum modulo $m$.
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CF 103973A - Monster Killer

We are simulating a sequential combat game where a player fights monsters one after another in a fixed order. Each monster has a fixed attack threshold, and the player maintains a single integer state representing their current attack ability.
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CF 103973C - Roll the Circle

We are given two circles with radii $a$ and $b$. One circle is fixed in place, and the other circle is placed tangent to it from the outside.
codeforces competitive-programming Jul 2, 2026