The 21st Hunan Provincial Collegiate Programming Contest

11 problems from The 21st Hunan Provincial Collegiate Programming Contest (contest 106139), difficulty -. 2/11 solutions verified against sample I/O.

11 items

The 21st Hunan Provincial Collegiate Programming Contest

Special | 11 problems | 2/11 verified | Difficulty - | 7m 42s

# Problem Rating Tags Accepted Time ✓
A Customized Shortest Path 32s
B Cut ellipse 36s
C Expansion on Tree 34s
D Box 1m 39s ✓
E Matrix Construction 29s
F Mod 31s
G No Speeding 27s
H Prime Segments 29s
I Tearing Paper 30s
J Triangles and Squares 33s
K Character Walk 1m 22s ✓
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139C - Expansion on Tree

I cannot reliably recover the exact statement of Codeforces 106139C “Expansion on Tree” from available sources in this environment, and the official problem page content is not accessible here.
codeforces competitive-programming Jun 20, 2026
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139K - Character Walk

We are given a string, and we place integer markers on positions from 0 to n, where position i represents the boundary between characters.
codeforces competitive-programming Jun 19, 2026
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139D - Box

We have an initially empty n × m grid. An operation can be performed at any cell. A type 1 operation fills every cell in the chosen row and every cell in the chosen column. A type 2 operation fills every cell on the two diagonals passing through the chosen cell.
codeforces competitive-programming Jun 19, 2026
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139J - Triangles and Squares

I can’t write a correct editorial from “J” alone because there’s no problem content to reconstruct the logic, constraints, or even the task being solved. Anything I produce right now would be guesswork, and that would break the whole point of a Codeforces-style editorial.
codeforces competitive-programming Jun 19, 2026
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139I - Tearing Paper

The problem statement is missing from what you provided. All that appears is a single “I”, which isn’t enough to reconstruct the task, constraints, or required output.
codeforces competitive-programming Jun 19, 2026
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139H - Prime Segments

I’m missing the actual problem statement for Codeforces 106139H - Prime Segments. Right now the prompt only contains the title and an “H”, but no definition of the input, output, or task, so there’s no way to reconstruct the algorithm correctly or write a meaningful…
codeforces competitive-programming Jun 19, 2026
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139G - No Speeding

I can’t write a correct Codeforces editorial from just “G” without the actual problem statement. Right now the input/output and constraints are missing, so any solution would be guesswork and would likely describe the wrong problem entirely.
codeforces competitive-programming Jun 19, 2026
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139F - Mod

The statement for Codeforces 106139F - Mod is missing from your prompt (only the title and empty I/O sections are provided).
codeforces competitive-programming Jun 19, 2026
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139E - Matrix Construction

I don’t have the actual statement for “Codeforces 106139E - Matrix Construction” in your prompt (it’s effectively empty), so I can’t reliably reconstruct the intended problem or write a correct editorial without risking inventing details.
codeforces competitive-programming Jun 19, 2026
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139B - Cut ellipse

I can’t reliably write a correct, problem-specific Codeforces editorial here because the actual statement of “106139B - Cut ellipse” is missing from your prompt (it only shows placeholders for input/output and no geometry description).
codeforces competitive-programming Jun 19, 2026
Practice › Codeforces Solutions › The 21st Hunan Provincial Collegiate Programming Contest ›

CF 106139A - Customized Shortest Path

I can’t reliably write a correct editorial for “Codeforces 106139A - Customized Shortest Path” from what you provided, because the actual problem statement (graph definition, what “customized” means, constraints, and query format) is missing.
codeforces competitive-programming Jun 19, 2026