AtCoder Regular Contest 119
E
Pancakes
AtCoder
⌀ 2502
原题
← DF →
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Problem Statement

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We have a pancake tower which is a pile of $N$ pancakes. Initially, the $i$-th pancake from the top $(1 \leq i \leq N)$ has a size of $A_i$. Takahashi, a chef, can do the following operation at most once.

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  • Choose integers $l$ and $r$ $(1 \leq l \lt r \leq N)$ and turn the $l$-th through $r$-th pancakes upside down, reversing the order.
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Find the minimum possible ugliness of the tower after the operation is done (or not), defined below:

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the ugliness is the sum of the differences of the sizes of adjacent pancakes; that is, the value $|A^{\prime}_1 - A^{\prime}_2| + |A^{\prime}_2 - A^{\prime}_3| + \cdots + |A^{\prime}_{N-1} - A^{\prime}_N|$, where $A^{\prime}_i$ is the size of the $i$-th pancake from the top.

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Constraints

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  • $2 \leq N \leq 300000$
  • $1 \leq A_i \leq 10^9$
  • All values in input are integers.
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Input

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Input is given from Standard Input in the following format:

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N
A_1 A_2 \cdots A_N

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Output

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Print the minimum possible ugliness of the tower.

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样例

Input #1
5
7 14 12 2 6
Output #1
17
If we do the operation choosing $l = 2$ and $r = 5$, the pancakes will have the sizes of $7, 6, 2, 12, 14$ from top to bottom. The ugliness here is $|7-6| + |6-2| + |2-12| + |12-14| = 1 + 4 + 10 + 2 = 17$. This is the minimum value possible; there is no way to achieve less ugliness.
Input #2
3
111 119 999
Output #2
888
In this sample, not doing the operation minimizes the ugliness. In that case, the pancakes will have the sizes of $111, 119, 999$ from top to bottom, for the ugliness of $|111-119| + |119-999| = 8 + 880 = 888$.
Input #3
6
12 15 3 4 15 7
Output #3
19
If we do the operation choosing $l = 3$ and $r = 5$, the pancakes will have the sizes of $12, 15, 15, 4, 3, 7$ from top to bottom. The ugliness here is $|12-15| + |15-15| + |15-4| + |4-3| + |3-7| = 3 + 0 + 11 + 1 + 4 = 19$, which is the minimum value possible.
Input #4
7
100 800 500 400 900 300 700
Output #4
1800
If we do the operation choosing $l = 2$ and $r = 4$, the pancakes will have the sizes of $100, 400, 500, 800, 900, 300, 700$ from top to bottom, for the ugliness of $1800$.
Input #5
10
535907999 716568837 128214817 851750025 584243029 933841386 159109756 502477913 784673597 603329725
Output #5
2576376600
题目信息
题号
arc119_e
时间限制
2 s
内存限制
1024 MB

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