The 2023 ICPC Asia EC Regionals Online Contest (I)

12 problems from The 2023 ICPC Asia EC Regionals Online Contest (I) (contest 104639), difficulty -. 12/12 solutions verified against sample I/O.

12 items

The 2023 ICPC Asia EC Regionals Online Contest (I)

ICPC/IOI | 12 problems | 12/12 verified | Difficulty - | 10m 48s

# Problem Rating Tags Accepted Time ✓
A Qualifiers Ranking Rules 56s ✓
B String 54s ✓
C Multiply Then Plus 53s ✓
D Transitivity 58s ✓
E Magical Pair 50s ✓
F Alice and Bob 1m 7s ✓
G Spanning Tree 51s ✓
H Range Periodicity Query 1m 15s ✓
I Pa?sWorD 1m 1s ✓
J Minimum Manhattan Distance 48s ✓
K Minimum Euclidean Distance 34s ✓
L KaChang! 41s ✓
Practice › Codeforces Solutions › The 2023 ICPC Asia EC Regionals Online Contest (I) ›

CF 104639L - KaChang!

We are given a reference program whose running time is fixed at $T$, and a list of $n$ other programs with known running times.
codeforces competitive-programming Jun 29, 2026
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CF 104639K - Minimum Euclidean Distance

We are given a convex polygon that represents a safe region in the plane. For every airdrop query, we also get a circle defined by its diameter endpoints. Each airdrop lands uniformly at random anywhere inside that circle.
codeforces competitive-programming Jun 29, 2026
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CF 104639J - Minimum Manhattan Distance

We are given two geometric objects in the plane. Each object is a circle, but instead of being defined by a center and radius, each circle is specified by the endpoints of a diameter.
codeforces competitive-programming Jun 29, 2026
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CF 104639H - Range Periodicity Query

We are building a sequence of strings S1 through Sn by processing a string of operations. Starting from an empty string, each step adds exactly one character either to the left or to the right. If the current operation is a lowercase letter, we place it at the front.
codeforces competitive-programming Jun 29, 2026
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CF 104639I - Pa?sWorD

We are given a partially known password string of length n. Each position already restricts what the final password character can be.
codeforces competitive-programming Jun 29, 2026
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CF 104639G - Spanning Tree

We are given a process that builds a spanning tree in a somewhat indirect way. Initially, every node is isolated. Then we perform $n-1$ operations. Each operation provides two nodes $ai$ and $bi$, and at that moment both belong to different connected components.
codeforces competitive-programming Jun 29, 2026
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CF 104639F - Alice and Bob

We are given an array of integers and a two-player game defined on it. Alice moves first, and in each move a player picks any two positions in the array and replaces those two values with a new pair of integers that preserves their sum while strictly decreasing their absolute…
codeforces competitive-programming Jun 29, 2026
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CF 104639D - Transitivity

We are given an undirected simple graph where some pairs of vertices are already connected by edges. The operation we are allowed to perform is to add new edges, but we cannot delete existing ones and we cannot introduce parallel edges or self loops.
codeforces competitive-programming Jun 29, 2026
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CF 104639E - Magical Pair

We are given a prime number $n$. We consider all ordered pairs of positive integers $(x, y)$ where both values lie in the range $1 le x, y le n^2 - n$.
codeforces competitive-programming Jun 29, 2026
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CF 104639A - Qualifiers Ranking Rules

We are given the ordered results of two separate programming contests. Each contest ranks individual teams, but what ultimately matters is the performance of universities rather than individual teams.
codeforces competitive-programming Jun 29, 2026
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CF 104639B - String

We are given two strings of equal length, call them S1 and S2. Think of them as two aligned rows of characters, both indexed from 1 to n.
codeforces competitive-programming Jun 29, 2026
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CF 104639C - Multiply Then Plus

We are maintaining a dynamic collection of pairs of integers. Each pair behaves like a linear function in a single variable: for a pair $(ai, bi)$, we can evaluate a value $fi(x) = ai cdot x + bi$. The system supports two operations over time.
codeforces competitive-programming Jun 29, 2026