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No.1368 Kadomatsu Sequences Sleeping in a Cycle

レベル : / AI推定難易度 : 1125 / 実行時間制限 : 1ケース 2.000秒 / メモリ制限 : 256 MB / 標準ジャッジ問題
タグ : (AC するまで非表示) / 解いたユーザー数 137
作問者 : mai / テスター : first_vil
お気に入りにしたユーザー ProblemId : 4270 / 自分の提出
問題文最終更新日: 2021-01-07 02:19:43
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yukicoder contest 280 (門松コンテスト) (順位表) の他の問題:

Definition

A sequence $v = (a_1,a_2,a_3)$ consisting of 3 elements is said to be a Kadomatsu sequence if $v$ satisfies the following conditions.

  1. $a_1,a_2,a_3$ are all distinct
  2. Among the 3 elements, $a_2$ is the largest or the smallest

Problem Statement

$N$ integers $A_1,\ldots,A_N$ are arranged clockwise in a circle.
Seen from the center of the circle, the right neighbor of $A_i$ is $A_{i+1}$. Also, the right neighbor of $A_N$ is $A_1$.

If the sequence obtained by taking some 3 consecutive elements in their original order is a Kadomatsu sequence, they can be made into a group.
Each element can belong to at most one group; it cannot belong to two or more groups.

Here, the score of a group is defined as the value of the leftmost integer among its 3 elements, as seen from the center of the circle.
Output the maximum possible sum of the scores of the groups when the groups are formed appropriately.
If no groups are formed, the sum of the scores of the groups is $0$.

Input

A single input may contain multiple test cases.

The first line gives the number of test cases $T$.
Each test case is then given in the following 2 lines each.

$T$
$N_1$
$A_{1,1}\ \ldots\ A_{1,N_1}$
$\vdots$
$N_T$
$A_{T,1}\ \ldots\ A_{T,N_T}$

$1 \le T \le 2\times 10^4$
$3 \le N_j \le 2\times 10^5$
$1\le A_{j, i} \le 2\times 10^5$
$\sum_{j\in 1\ldots T}N_j \le 2\times 10^5$

All values in the input are integers.

Output

For each test case, output the maximum sum of the scores of the groups, separated by newlines.
Add a newline at the end.

Sample

Sample 1
Input
3
3
1 2 3
6
2 1 99 2 3 1
4
1 1 1 1
Output
3
99
0

In the first test case, grouping as [3 1 2] gives the maximum value $3$.
Grouping as [2 3 1] is also possible, but in this case the sum of the scores is $2$, so it is not optimal.

In the second test case, grouping as [99 2 3] gives the maximum value $99$. [1 2 1] is not a Kadomatsu sequence, so it cannot be grouped.
It is also possible to group as [2 1 99] [2 3 1]. In this case there are more groups, but the sum of the scores is $2+2=4$, so it is not optimal.

In the third test case, not a single group can be formed.

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