最美情侣中文字幕电影,在线麻豆精品传媒,在线网站高清黄,久久黄色视频

歡迎光臨散文網(wǎng) 會員登陸 & 注冊

CF 1726A - Mainak and Array

2023-06-30 15:00 作者:您是打尖兒還是住店呢  | 我要投稿

Mainak has an array a1,a2,…,an of n positive integers. He will do the following operation to this array exactly once:

Pick a subsegment of this array and cyclically rotate it by any amount.

Formally, he can do the following exactly once:

Pick two integers l and r, such that 1≤l≤r≤n, and any positive integer k.

Repeat this k times: set al=al+1,al+1=al+2,…,ar?1=ar,ar=al (all changes happen at the same time).

Mainak wants to maximize the value of (an?a1) after exactly one such operation. Determine the maximum value of (an?a1) that he can obtain.

Input

Each test contains multiple test cases. The first line contains a single integer t (1≤t≤50) — the number of test cases. Description of the test cases follows.

The first line of each test case contains a single integer n (1≤n≤2000).

The second line of each test case contains n integers a1,a2,…,an (1≤ai≤999).

It is guaranteed that the sum of n over all test cases does not exceed 2000.


Output

For each test case, output a single integer — the maximum value of (an?a1)

?that Mainak can obtain by doing the operation exactly once.


Example

input

5

6

1 3 9 11 5 7

1

20

3

9 99 999

4

2 1 8 1

3

2 1 5

output

10

0

990

7

4

Note

In the first test case, we can rotate the subarray from index 3 to index 6 by an amount of 2

?(i.e. choose l=3, r=6 and k=2) to get the optimal array:

[1,3,9,11,5,7–––––––––]?[1,3,5,7,9,11–––––––––]

So the answer is an?a1=11?1=10.

In the second testcase, it is optimal to rotate the subarray starting and ending at index 1

?and rotating it by an amount of 2.

In the fourth testcase, it is optimal to rotate the subarray starting from index 1 to index 4

?and rotating it by an amount of 3. So the answer is 8?1=7.

---------------------------

對于每個ai,旋轉(zhuǎn)的話,可以1-i旋轉(zhuǎn),也可以n-i旋轉(zhuǎn),這樣一個是把ai轉(zhuǎn)到a1的位置,一個是把ai轉(zhuǎn)到an的位置了,但是這里面還有個條件就是可以一直旋轉(zhuǎn),這樣的話,就存在ai ai+1分別在an a1的位置的,所以還要把這種情況考慮進去。

然后就可以AC了;


CF 1726A - Mainak and Array的評論 (共 條)

分享到微博請遵守國家法律
自治县| 东安县| 深州市| 自贡市| 蒙城县| 华安县| 图片| 资源县| 开封市| 资中县| 云霄县| 长兴县| 页游| 清苑县| 大英县| 灯塔市| 阿荣旗| 武邑县| 武威市| 兰西县| 建昌县| 抚松县| 读书| 安化县| 永修县| 嵊州市| 保定市| 隆子县| 阳东县| 新密市| 神农架林区| 营山县| 台前县| 丰原市| 旅游| 荣昌县| 巨鹿县| 土默特右旗| 肃宁县| 茂名市| 宜章县|