QOJ.ac

QOJ

Time Limit: 1.0 s Memory Limit: 1024 MB Total points: 100 Hackable ✓

#15435. Dumb Problem

统计

给定一个长度为 $n$ 的整数序列:$a_1, a_2, \dots, a_n$。你可以执行以下操作恰好一次:

  • 选择 $1, 2, \dots, n$ 的一个排列 $p_1, p_2, \dots, p_n$。
  • 然后,对于 $i$ 从 $1$ 到 $n$ 按自然顺序执行:

$$a_{p_i} \leftarrow a_{p_i} + a_{p_i-1} + a_{p_i+1},$$

其中 $a_0 = 0$ 且 $a_{n+1} = 0$。

你的目标是最大化操作完成后序列中所有元素的总和。

输入格式

第一行包含一个整数 $t$ ($1 \le t \le 10^4$),表示测试用例的数量。对于每个测试用例:

第一行包含一个整数 $n$ ($1 \le n \le 2 \cdot 10^5$)。

第二行包含 $n$ 个整数 $a_1, a_2, \dots, a_n$ ($-10^8 \le a_i \le 10^8$)。

所有测试用例中 $n$ 的总和不超过 $2 \cdot 10^5$。

输出格式

对于每个测试用例,输出一行一个整数,表示执行操作后序列中所有元素可能的最大总和。

样例

输入格式 1

4
3
1 2 3
4
-1 3 7 6
5
4 1 0 5 2
6
4 -3 7 5 -9 3

输出格式 1

22
85
72
79

Discussions

About Discussions

The discussion section is only for posting: General Discussions (problem-solving strategies, alternative approaches), and Off-topic conversations.

This is NOT for reporting issues! If you want to report bugs or errors, please use the Issues section below.

Open Discussions 0
No discussions in this category.

Issues

About Issues

If you find any issues with the problem (statement, scoring, time/memory limits, test cases, etc.), you may submit an issue here. A problem moderator will review your issue.

Guidelines:

  1. This is not a place to publish discussions, editorials, or requests to debug your code. Issues are only visible to you and problem moderators.
  2. Do not submit duplicated issues.
  3. Issues must be filed in English or Chinese only.
Active Issues 0
No issues in this category.
Closed/Resolved Issues 0
No issues in this category.