AtCoder Beginner Contest 128
D
equeue
AtCoder
⌀ 1354
原题
← CE →
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Problem Statement

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Your friend gave you a dequeue $D$ as a birthday present.

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$D$ is a horizontal cylinder that contains a row of $N$ jewels.

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The values of the jewels are $V_1, V_2, ..., V_N$ from left to right. There may be jewels with negative values.

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In the beginning, you have no jewel in your hands.

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You can perform at most $K$ operations on $D$, chosen from the following, at most $K$ times (possibly zero):

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  • Operation A: Take out the leftmost jewel contained in $D$ and have it in your hand. You cannot do this operation when $D$ is empty.
  • Operation B: Take out the rightmost jewel contained in $D$ and have it in your hand. You cannot do this operation when $D$ is empty.
  • Operation C: Choose a jewel in your hands and insert it to the left end of $D$. You cannot do this operation when you have no jewel in your hand.
  • Operation D: Choose a jewel in your hands and insert it to the right end of $D$. You cannot do this operation when you have no jewel in your hand.
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Find the maximum possible sum of the values of jewels in your hands after the operations.

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Constraints

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  • All values in input are integers.
  • $1 \leq N \leq 50$
  • $1 \leq K \leq 100$
  • $-10^7 \leq V_i \leq 10^7$
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Input

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Input is given from Standard Input in the following format:

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N K
V_1 V_2 ... V_N

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Output

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Print the maximum possible sum of the values of jewels in your hands after the operations.

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样例

Input #1
6 4
-10 8 2 1 2 6
Output #1
14
After the following sequence of operations, you have two jewels of values $8$ and $6$ in your hands for a total of $14$, which is the maximum result. - Do operation A. You take out the jewel of value $-10$ from the left end of $D$. - Do operation B. You take out the jewel of value $6$ from the right end of $D$. - Do operation A. You take out the jewel of value $8$ from the left end of $D$. - Do operation D. You insert the jewel of value $-10$ to the right end of $D$.
Input #2
6 4
-6 -100 50 -2 -5 -3
Output #2
44
Input #3
6 3
-6 -100 50 -2 -5 -3
Output #3
0
It is optimal to do no operation.
题目信息
题号
abc128_d
时间限制
2 s
内存限制
1024 MB

题面与样例版权归 AtCoder 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。