2084. Bad Neighbors

单点时限: 2.0 sec

内存限制: 256 MB

The old song declares “Go ahead and hate your neighbor”, and the residents of Onetinville have taken those words to heart. Every resident hates his next-door neighbors on both sides. Nobody is willing to live farther away from the town’s well than his neighbors, so the town has been arranged in a big circle around the well. Unfortunately, the town’s well is in disrepair and needs to be restored. You have been hired to collect donations for the Save Our Well fund.

输入格式

Each of the town’s residents is willing to donate a certain amount, as specified in the vector donations, which is listed in clockwise order around the well. However, nobody is willing to contribute to a fund to which his neighbor has also contributed. Next-door neighbors are always listed consecutively in donations, except that the first and last entries in donations are also for next-door neighbors.

-donations contains between 2 and 40 elements, inclusive.

-Each element in donations is between 1 and 1000, inclusive.

输出格式

You must calculate and return the maximum amount of donations that can be collected.

样例

Input
6
10 3 2 5 7 8
/*
40
94 40 49 65 21 21 106 80 92 81 679 4 61 6 237 12 72 74 29 95 265 35 47 1 61 397 52 72 37 51 1 81 45 435 7 36 57 86 81 72
*/
Output
19
The maximum donation is 19, achieved by 10+2+7. It would be better to take 10+5+8 except that the 10 and 8 donations are from neighbors.
/*
2926
*/

17 人解决,27 人已尝试。

21 份提交通过,共有 50 份提交。

5.2 EMB 奖励。

创建: 11 年,11 月前.

修改: 2 年,5 月前.

最后提交: 1 年,10 月前.

来源: TC

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