P14836 [CodeChef] CIRMERGE
提高
题目描述

Read problem statements in [Hindi], [Bengali], [Mandarin Chinese], [Russian], and [Vietnamese] as well.

$N$ integers $A_{1}, A_{2}, \ldots, A_{N}$ are placed in a circle in such a way that for each valid $i$, $A_{i}$ and $A_{i+1}$ are adjacent, and $A_{1}$ and $A_{N}$ are also adjacent.

We want to repeat the following operation exactly $N-1$ times (until only one number remains):
Select two adjacent numbers. Let's denote them by $a$ and $b$.
Score $a+b$ penalty points.
Erase both $a$ and $b$ from the circle and insert $a+b$ in the space between them.

What is the minimum number of penalty points we can score?

------ Input ------
The first line of the input contains a single integer $T$ denoting the number of test cases. The description of $T$ test cases follows.
The first line of each test case contains a single integer $N$.
The second line contains $N$ space-separated integers $a_{1}, a_{2}, \ldots, a_{N}$.

------ Output ------
For each test case, print a single line containing one integer — the minimum number of penalty points.

------ Constraints ------
$1 ≤ T ≤ 10$
$2 ≤ N ≤ 400$
$1 ≤ a_{i} ≤ 10^{9}$ for each valid $i$

------ Subtasks ------
Subtask #1 (10 points):
$2 ≤ N ≤ 10$
$a_{i} ≤ 10$ for each valid $i$

Subtask #2 (10 points):
$2 ≤ N ≤ 25$
$a_{1}, a_{2}, \ldots, a_{N}$ are distinct powers of $2$ (including $1$)

Subtask #3 (10 points): $2 ≤ N ≤ 100$

Subtask #4 (70 points): original constraints

----- Sample Input 1 ------
1
3
10 10 1
----- Sample Output 1 ------
32
----- explanation 1 ------
- $[10,10,1] \rightarrow [10, 11]$, penalty: $11$
- $[10,11] \rightarrow [21]$, penalty: $21$
- Total penalty: $11+21=32$

输入格式

见题面

输出格式

见题面

样例输入
1 3 10 10 1
样例输出
32