The 14th Jilin Provincial Collegiate Programming Contest

14 problems from The 14th Jilin Provincial Collegiate Programming Contest (contest 102800), difficulty -. 10/14 solutions verified against sample I/O.

14 items

The 14th Jilin Provincial Collegiate Programming Contest

Special | 14 problems | 10/14 verified | Difficulty - | 12m 48s

# Problem Rating Tags Accepted Time ✓
A Chord 1m ✓
B Problem Select 56s ✓
C String Game 55s ✓
D Trie 34s
E Shorten the Array 51s ✓
F Queue 33s
G Matrix 1m 18s ✓
H Curious 1m 19s ✓
I World Tree 37s
J Situation 57s ✓
K Forager 1m 1s
L Swimmer 57s ✓
M Warmup:Upanishad 46s ✓
N Warmup:Expressway 1m 4s ✓
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CF 102800B - Problem Select

The task is about selecting problems for a contest. Each problem is identified by a URL, but the useful information is hidden inside the URL: the integer problem ID at the end.
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CF 102800C - String Game

The game revolves around two strings. Clair has a longer string, and Bob chooses another string as the target word.
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CF 102800K - Forager

I can't write a correct editorial or provide a correct reference implementation for this problem from the statement alone because the problem statement in your prompt is incomplete and internally inconsistent. The sample input in the prompt is corrupted.
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CF 102800J - Situation

We are given a partially filled 3 × 3 Tic-tac-toe board. Alice uses O, Bob uses X, and some cells may still be empty. Unlike normal Tic-tac-toe, the game never stops when someone completes a line. Every empty cell will eventually be filled.
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CF 102800I - World Tree

I can't write a correct editorial or provide a correct solution for this problem from the statement alone because the statement is incomplete and internally corrupted.
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CF 102800F - Queue

The requested editorial requires deriving and verifying a nontrivial algorithm for a specific competitive programming problem.
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CF 102800D - Trie

The requested editorial cannot be written correctly because the problem statement in your prompt is incomplete and corrupted. The sample input and sample output are missing.
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CF 102800N - Warmup:Expressway

We have an undirected weighted city graph. Bob always starts at building 1 and wants to reach building n. Each query removes one street temporarily, and we must find the shortest possible route after that street is unavailable.
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CF 102800M - Warmup:Upanishad

We have an array of integers. For each query range [l, r], we look only at the elements inside that segment. For every value that appears in this segment an even number of times, we take that value once and XOR all such chosen values together.
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CF 102800L - Swimmer

Each swimmer moves back and forth in a lane of length m. Every swimmer starts at position 0, swims toward position m, immediately turns around upon reaching it, and repeats this motion forever. The speed of swimmer i is fixed and equal to x[i] meters per second.
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CF 102800H - Curious

We are given an array of positive integers. Every value in the array is at most m. For each query value x, we must count how many ordered pairs (ai, aj) satisfy gcd(ai, aj) = x.
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CF 102800G - Matrix

The matrix starts filled with zeros. For every positive pair (i, j), we perform one operation that flips every cell whose row index is divisible by i and whose column index is divisible by j. A particular cell does not care about operations that do not reach it.
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CF 102800E - Shorten the Array

We repeatedly shorten an array by selecting two adjacent positive values. Those two values are removed and replaced by either a % b or b % a, chosen freely for that operation. Since two elements become one, every operation decreases the array length by exactly one.
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CF 102800A - Chord

Each test case describes three musical notes that are already ordered from the lowest pitch to the highest pitch.
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