Codeforces Round 782 (Div. 2)
C
Line Empire
Codeforces
1500
原题
← BD →
翻译中…

You are an ambitious king who wants to be the Emperor of The Reals. But to do that, you must first become Emperor of The Integers.

翻译中…

Consider a number axis. The capital of your empire is initially at $0$. There are $n$ unconquered kingdoms at positions $0 \lt x_1 \lt x_2 \lt \ldots \lt x_n$. You want to conquer all other kingdoms.

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There are two actions available to you:

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  • You can change the location of your capital (let its current position be $c_1$) to any other conquered kingdom (let its position be $c_2$) at a cost of $a\cdot |c_1-c_2|$.
  • From the current capital (let its current position be $c_1$) you can conquer an unconquered kingdom (let its position be $c_2$) at a cost of $b\cdot |c_1-c_2|$. You cannot conquer a kingdom if there is an unconquered kingdom between the target and your capital.
翻译中…

Note that you cannot place the capital at a point without a kingdom. In other words, at any point, your capital can only be at $0$ or one of $x_1,x_2,\ldots,x_n$. Also note that conquering a kingdom does not change the position of your capital.

翻译中…

Find the minimum total cost to conquer all kingdoms. Your capital can be anywhere at the end.

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Input

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The first line contains a single integer $t$ ($1 \le t \le 1000$)  — the number of test cases. The description of each test case follows.

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The first line of each test case contains $3$ integers $n$, $a$, and $b$ ($1 \leq n \leq 2 \cdot 10^5$; $1 \leq a,b \leq 10^5$).

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The second line of each test case contains $n$ integers $x_1, x_2, \ldots, x_n$ ($1 \leq x_1 \lt x_2 \lt \ldots \lt x_n \leq 10^8$).

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The sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

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Output

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For each test case, output a single integer  — the minimum cost to conquer all kingdoms.

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Note

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Here is an optimal sequence of moves for the second test case:

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  1. Conquer the kingdom at position $1$ with cost $3\cdot(1-0)=3$.
  2. Move the capital to the kingdom at position $1$ with cost $6\cdot(1-0)=6$.
  3. Conquer the kingdom at position $5$ with cost $3\cdot(5-1)=12$.
  4. Move the capital to the kingdom at position $5$ with cost $6\cdot(5-1)=24$.
  5. Conquer the kingdom at position $6$ with cost $3\cdot(6-5)=3$.
  6. Conquer the kingdom at position $21$ with cost $3\cdot(21-5)=48$.
  7. Conquer the kingdom at position $30$ with cost $3\cdot(30-5)=75$.
翻译中…

The total cost is $3+6+12+24+3+48+75=171$. You cannot get a lower cost than this.

翻译中…

样例

Input #1
4
5 2 7
3 5 12 13 21
5 6 3
1 5 6 21 30
2 9 3
10 15
11 27182 31415
16 18 33 98 874 989 4848 20458 34365 38117 72030
Output #1
173
171
75
3298918744
InputCopy OutputCopy
题目信息
题号
1659C
时间限制
1 s
内存限制
256 MB
标签
二分
暴力
动态规划
贪心
模拟
数学

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。