The 15th Huazhong Agricultural University Programming Contest

13 problems from The 15th Huazhong Agricultural University Programming Contest (contest 106456), difficulty -. 12/13 solutions verified against sample I/O.

13 items

The 15th Huazhong Agricultural University Programming Contest

Special | 13 problems | 12/13 verified | Difficulty - | 12m 26s

#	Problem	Time	✓
A	Your Shine Your Be!	1m 12s	✓
B	Bus Game	51s	✓
C	Crossing	1m 12s	✓
D	Taffy's LCM	47s	✓
E	Simple Math	51s	✓
F	Fanfan's Bracket Sequence	50s	✓
G	Taffy vs Goblins	1m 2s	✓
H	Little t's Recurrence	25s
I	Milk Tea	44s	✓
J	Tree	1m 12s	✓
K	MEX	1m 11s	✓
L	Tornado Destroys the Parking Lot	1m 1s	✓
M	Little t's GCD	1m 8s	✓

Practice › Codeforces Solutions › The 15th Huazhong Agricultural University Programming Contest ›

CF 106456G - Taffy vs Goblins

Each test case describes a fixed battle scenario with N independent attacks. Attack i targets goblin i and either deals full damage Ci or nothing, depending on whether its penetration Ai reaches the goblin’s defense Bi.

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CF 106456K - MEX

We are given a tree where every vertex carries a distinct label from the set $0,1,dots,n-1$. Because the labels form a permutation, each value corresponds to exactly one node, so thinking in terms of values or nodes is interchangeable.

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CF 106456L - Tornado Destroys the Parking Lot

The parking lot is a grid where each cell is either empty or contains a car that has a fixed direction of movement.

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CF 106456C - Crossing

We are given a grid where each cell contains a non-negative integer. A traveler starts at the top-left cell and must reach the bottom-right cell. Movement is allowed in four directions and cells may be revisited any number of times.

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CF 106456E - Simple Math

We are given a positive integer $x$, and we want to know whether there exists another positive integer $k$ such that the product $x cdot k$ becomes a number consisting only of the digit 9 in every position.

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CF 106456A - Your Shine Your Be!

We are given an array of non-negative integers. Each query asks about a subarray defined by a range, but the actual range is not given directly.

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CF 106456M - Little t's GCD

We are given a sequence of positive integers and we are allowed to split it into several contiguous segments that together cover the entire array. For each segment, we compute two quantities. The first quantity depends only on the segment indices.

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CF 106456I - Milk Tea

We are asked to compute the cheapest way to buy exactly n cups of milk tea when the shop offers two purchase options: buying a single cup for cost a, or buying a bundle of two cups for cost b. Each bundle is indivisible and gives exactly two cups.

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CF 106456D - Taffy's LCM

We are given multiple independent queries. Each query provides a single integer $c$. For each $c$, we must split it into two positive integers $a$ and $b$ such that $a + b = c$.

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CF 106456J - Tree

We are given a rooted tree where every node carries a numeric value. The tree is fixed, but the values change over time under constraints that preserve a global monotonic property: every parent must always have a value at least as large as each of its children.

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CF 106456F - Fanfan's Bracket Sequence

We are given a rooted binary tree whose nodes are labeled from 1 to n. Each node corresponds to one pair of matching parentheses in some unknown valid bracket sequence of length 2n.

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CF 106456H - Little t's Recurrence

Sure. Please provide the full Codeforces problem statement (or the problem link/code), and I'll write a comprehensive competitive-programming editorial including: - Problem observation and intuition - Key insights - Proof of correctness - Algorithm design - Complexity analysis…

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CF 106456B - Bus Game

We are given a line of seats, each seat either usable or broken. Two players alternate placing passengers onto usable seats, starting with Alice.